Wooden Floors

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W OODEN FLOORS 1LAYING AND REPAIRING

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W O O D



W OODEN FLOORS 1

THE WOOD INDUSTRY ADVISORY COUNCIL(TRÆBRANCHENSOPLYSNINGSR ÅD)

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PREFACE

It is the aim of this handbook to show testedmethods for the laying of wooden floors and

to sum up such design assumptions that arerequired in order to construct wooden floorscorrectly. The choise of wooden floors aswell as maintenance are described inWOOD 47, Wooden Floors 2 .Both handbooks build on practical

experience and take into consideration suchconditions that are applicable toconstruction work and to wood as a buildingmaterial.

The exposure to moisture duringconstruction and the inappropriatemoistening of the wooden floor during usemay cause undesired danmages because notall materials and not all workmanship arecompatible with wooden materials. Most

building materials expand and contractwhen temperature changes, whereas woodexpands and contracst with changinghumidity.

It is important to take into considerationthe particular relation between wood andhumidity both when laying and whenmaintaining wooden floors. The floors must

be able to contract and expand independentlyfrom other building components. Alsowooden floor should be laid as late as

possible in the building process in order tosecure that the indoor climate is sufficientlydry. In relation to moisture and exposure tomoisture it is important to treat woodenfloors exactly as one one treat fixedfurniture and furniture

In spite of different construction principles wooden floors are a natural

product with the variations in the materialwhich characterizes wood.The quality of the wooden floor therefore

highly depends on proper grading of woodand on wood quality as well as thesubsequent workmanship and maintenance.There may be variations in the surfacestructure of the wood, in the colour, in thegrain pattern and in the density.

It is such variations which, within certainlimits, add the life and glow characteristicto natural materials.

As wood adjusts to the variations in air humidity during the seasons of the year there will be natural variations in the widthsof the boards and therefore in the widths of the joints. Normally, the joints are closedduring the summer and open open during thewinter.

This handbook primarily addressesconsultants and craftsmen within the

building industry, but has been so plannedthat it may be used by clients, real estateadministators do-it-yourself people and as alecturing aid in building design.

In order to achive the widest possible professional approach the handbook has been elaborated in conjunction with floor material suppliers and trade associationswho have most willingly contributed with

professional knowledge and practicalexperience.

Advisory Council for the Wood Industry (Træsbranchens Oplysningsråd)

June 2004Bjarne Lund Johansen



FLOOR TYPESWooden floors are floors made of planks,strips, blocks or laminatedmaterials with a wooden core. Woodenfloors may be divided into two maingroups defined by the constructionprinciple:Suspended floors include:• Floors on battens (blocked up)• Floors on joistsNon-suspended floor include:• Floating floors• Glued floors• Nailed floors

Suspended floorsSuspended floors are floors resting upona linear support of joists or battens. Theload on the floor is transferred throughthe boards and accepted by the under-laying battens or joists, see figure 1.

Floors on battens Battens are chocked up on an under-laying structural floor made of suchmaterials as concrete, clinker concreteor wood in order to establish a levelsurface for the wooden floor

Floors on joists Structural joists are the basic parts of a wooden floor partition on top of basements, crawl spaces and storeypartitions. Suspended wooden floors maybe constucted from planks or long stavestrip flooring. The planks may betraditional solid flooring boards or theymay be laminated parquet flooring.Long staves are extraordinarily longparquet staves. Floors on joists andbattens offer ample opportunities for theplacing of sound and heat insulatingmaterials in the cavity under thefloor.The cavity may also be used for the running of heating and electrical installations.

Figure 1 Suspended floors on battens and onstructural joists

Non-suspended floorsNon-suspended wooden floors aresupported throughout the floor surfaceby a structural sub floor made of for example concrete of from woodenboards

Floating floors Floating floors can move freely (inrelation to the sub floor) when the woodexpands and contracts with moisturevariations (figure 2)..

It is common practice to introduce anadditional layer between the woodenfloor and the sub floor in order to securethe free movement of the floor. Thislayer may be made of materialscontributing to thermal or soundinsulation (cork, foam or the like).

4 FLOOR TYPES

Battens(chocked up)

Floor on attens

Structural joists

Floor on joists



Undgulv

Figure 2 Non–suspended floors - floating

Floating floors may be laid on top of aload distributing board or directly on topof the intermediate layer.

Figure 3 Non-suspended floors – glued/nailed

Glued and nailed floors Glued and nailed wooden floors arealways fixed firmly on top of a plane andstable structural floor and supportedthroughout the entire surface, see figure 3.

The structural floor can be made of concrete, light weight concrete or awooden based sub floor or even afloating floor - for example made of glue joined boards. On structural wooden joists it will bepossible to use the sub floor as a “workfloor” during the construction period.The underlay floor could also be anexisting floor where a renovation isdesired – laying a new floor on top of the existing.

FLOOR MATRIALS 5

Additional layer Glue

Floor fixed with glueon concrete slabstructural floor

Floating floor - ontop of additionallayer (here cork)

GlueMoisture barrier

Additional layer wooden boardmaterial

Floating floor onadditional layer made from wooden

board material

Floor fixed with glueon structural floor made of wood

Structutal floor

Floating floor onstructural floor made of wooden

board material

Additional layer

Structural floor



Floor construction - terminologyThe uppermost independent layer of thefloor, i.e. the floor covering constitutesthe finished floor surface. The floor covering can be made of planks, parquetstaves, PVC or linoleum. Applied finishessuch as varnish or other surfacetreatments are not considered asindependent floor covers.Structural floors are placed under thefloor cover but above the structural

joists. The structural floor mustconstitute a continuous surface makingit suitable for example as a ”work floor”and as underlay for a thin floor cover.The structural floor can be made of wooden boarding laid on pressureresistant insulation, or laid onbattens,structural joists, or on aconcrete screed.Notice that thin insulation layers likecork based cardboard etc. areadditional layers and not regarded asstructural floors.The function of the structural floor construction is primarily to accept andtransfer loads. The structural floor construction could be wooden joists,concrete slabs etc. See figure 4

.

Figur 4 Floor construction -terminology

Table 1: An o verview of different flooring m aterials and th eir application in different floor constructions. The highlighted areas indicate that the product can be used for the said purpose.The text indicates limitations.

Foor types Floor materials

Floor boards

Stripflooring

Parquetflooring

boards

Mosaic parque t

Laminated parquetflooring

Laminate,melamine,veneer

Blocks

Suspended floorsFloors on floor battensor on floor joists

Minimumthickness20 mm

Long stavestripflooringminimum20 mmthickness

Minimum20 mmthickness

Minimumthickness22 mm

Non- suspended floor sFloating floors

Only onfloating sub-floor

Onlyclipsystem

Only onfloatingsub- floor

Only onfloatingsub- floor

Nailed floors inimum12 mmthick

hiddennailing

Minimum12 mmthick

hiddennailing

inimum12 mmthick

hiddennailing

Minimum12 mmthick

hiddennailing

Glued floors Short staves Ask supplier*

* Only in widths as specified by the supplier.

6 FLOOR TYPES

Floor cover

Additional layer Structural floor

Structural joistsStructural joists +Structural floor =structural floor construction



Floor materials

Floor boardsFloor boards are solid boards primarily

produced from softwoods such as pine,spruce, douglas or pitch pine. Hardwoods areused to a lesser extend for example oak or merbau.

Floor boards are planed, tongued andgrooved boards, normally produced inwidths ranging from 75 to 180 mm and inthicknesses from 14 to 30 mm.

It is possible to place special orders for thicknesses up to 40 mm and widths up to450. The length is normally between 1.8and 5.4 m. In case boards are ordered asrandom length it is possible that some

planks may be shorter. In case boards areordered with a fixed length, it is likely thatsome planks (normally 5-10%) will beshorter as the producer needs economizewhen cutting the tree trunk.

Because floor boards look like planks,they are sometimes called floor planksalthough the products do not have sufficientthickness to merit that term (a planedthickness of minimum 42 mm).

No standards have been defined for thedimensions and profiles of floor boards.That is why floor boards from differentmanufacturers will normally not fit together.

Tongue and groove are often placed nearer the bottom side of the board in order to

provide the floor boards with the thickest possible wearing layer. The bottom rebate ismade 0.5 mm deeper than the top rebate inorder to secure a tight fit between the

boards, see figure 5.Floor boards are often supplied with

socalled stress grooves at the bottom side inorder to counter the natural curving in the

boards. Stress grooves are only consideredeffective when they have a depthcorresponding to two thirds of the initialthickness of the board, i.e. before dryingand planning. Grooves on the bottom sideare not always stress grooves but may also

be socalled guiding grooves used inconnection with the profiling process.

Boards with a minimum thickness of 20mm may be laid directly on floor battens or

joists as a suspended floor. The distance between supports shall be determined inaccordance with thickness and load., seetables 3 and 4. Boards less than 20 mm inthickness require the existence of a sub-floor in order to get sufficient support.

FLOOR MATERIALS 7

-Tongue GrooveStress groove

Bottom rebate Guiding groove

Figure 5 Floor boards



Strip floor / parquet stavesParquet staves are normally single staves insolid wood. The staves are rectangular withtongue ans groove (T&G). However solidstaves are also available without T&G seefigure 6.

Parquet stavesare produced fromtraditional European wood species such as

beech, oak and ash but also such exoticspecies as padouk, merbau, doussie andwenge are used.

Parquet staves are normally 200-700 mmlong and 50-70 mm wide. Parquet stavesare also produced as so-called long staveswith a length of 700-1200 mm.

Parquet staves are either glued or nailed.Long staves with a minimum thickness of 20 mm may be laid as a suspended floor.

Parquet boardsParquet boards are made from solid parquetstaves joined together in a prefabrication

process. It is common practice to join twoor three staves in parallel, using a specialdovetail joint. The boards are supplied witha T&G along all four sides ad are suppliedin length as normal flooring boards seefigure 7.

Parquet boards can be laid using the samemethods as those used for ordinary flooring

boards, i.e. as a suspended floor when the board thickness is minimum 20 or as anailed floor on level structural floor..

Parquet boards may also be applied asfloating floors joined with purpose madeclips, see page 21.

8 FLOOR MATERIALS

29-Fer

Fas

Figure 6 Parquet staves

Dovetail joint- Tongue

Groove Groove for clip

Figure 7 Parquet boards



Parquet tilesParquet tiles are factory joined parquetstaves glued together to constitute larger units, see figure 8. Parquet tiles are laid as aglued floor.

Mosaic parquetMosaikparket bestar af sma enkeltstave,som er holdt sammen, sa de danner ruder/fliser, se figur 8. Stavene kan f.eks. vaerelimet til et abent basrelag af papir eller neteller vaere holdt sammen af staltrad. Papir eller net er normalt placeret pa parketru-dens bagside, men kan i stedet vasre limettil mosaikparkettens forside, og bortslibes isa fald efter laegningen. Mosaikparketleegges som et limet gulv.

Wood veneer flooring boardsWood veneer flooring boards are normallymade as a threee layer laminate.The bottom layer is made of soft wood withfibres oriented along the board. The core ismade of chipboard, plywood, MDF or cross

bonded wooden strips. The topmost layer consists of minimum 2 mm wood veneer. Inmost cases this layer is 3-4 mm thick. Thewood venner is separated into stavessimilar in appearance to solid parquetstaves, see figure 9. In this way it is

possible to obtain wood veneer flooring boards with appearance similar to floor boards and stave parquet. See figure 9.

Wood veneer flooring boards are laid asnormal floor boards, i.e. as a suspended floor

provided the thickness is minimum 22 mm.They can also be laid as floating floors or asglued or nailed floors.t .

Figure 9 Woodveneer flooring boards

FLOOR MATERIALS 9

Figur 8 Parquet tiles and mosaic parquet

Wood veneer surface

Bottom layer Core



Laminate flooring boardsLaminate flooring boards are compositeflooring boards with either a chipboard or MDF or HDF core that is bonded to a filmof wood effect veneer (lees than 2 mmthick) and covered with a laminated surface.It is not to be confused with wood veneer flooring boards. The bottom side is coveredwith a counter veneer made of pvc laminate,

paper or the like in order to prevent tensionsand in order to maintain planeness of the

board. See figure 10.Laminate flooring boards are supplied

different surfaces, colours and patternsmost of them imitating wood.

Laminate flooring boards with a thin layer of wood veneer are supplied in a variety of wood species and with surfaces as boards or with parquet pattern. All veneered boards aresupplied pre-varnished.

Laminate flooring boards and veneeredlaminate boards can be laid as floating floorsor as glued or nailed floors

End grain wood blocksEnd grain wood blocks are rectangular

wooden blocks made of oak, pine, spruceor larch. The length of the blocks shouldnot exceed 1.5 x the width. The blocks areavailable in thicknesses from 18 to 100mm, see figure 11.

The blocks are laid with fibres in vertical position. They are glued directly to theunderlay using special glue. The bestsuited underlay is a rigid board material.The blocks may also be glued directly ona dry concrete slab. Blocks with a thicknessexceeding 80 mm may alternatively be laidin sand.

Good quality blocks may be used asfloors in assembly rooms and dwellings. Itdoes, however, require a good finish andsurface treatment.

As the surface on this type of floor consists of end grain it is very susceptibleto moisture from the air as well as moisturefrom cleaning. It is therefore recommended

to avoid direct exposure to moisture and toconsult the manufacturer concerningmoisture expansion and the possible needfor dilatation joints.

er Top layer

Figur 10 Laminate flooring board veneered board.

Core

Figure 11 End grain wooden blocks

Bottom layer

10 FLOOR MATERIALS



SUBFLOOR

A prior condition to constructing a goodwooden floor is the establishment of a high

quality substrate only using materialswith adequate properties.

Floor battensFloor battens are made of solid wood or they may be made of laminated wood, seefigure 12. Solid wood floor battens shall befree of wane and should have a width of minimum 45 mm (planed dimension).Laminated battens (for example Kerto) shallhave a width of minimum 40 mm in order toeliminate the risk of splitting (when nailingor screwing). The battens should always beas long as possible as the best result will be

achieved with battens in full room length(no joints). Standard lengths go up to 3.9 mand it may be possible to order battens up to4.8 m.

Battens should be planed on the sidefacing the flooring boards. The battens must

be sufficiently straight to meet thesraightness requirements shown elsewhereon this page. After laying the battens thesideways deviation should not exceed 5mm when compared to a 2 m straightedge(placed on the concave side of the batten).Warping is only allowed to an extentwhereby a batten placed loosely on

Figure 12 Floor battens: Sawn battens (1), strip

laminated battens (2), plywood principle laminated battens, Ker to (3) . Reference is made to table 5 on page 47 for blocking u p dista nces for the d ifferenttypes.

Maximum 1/3Minimum 2/3

Figure 14 Floor battens requirements to knots

the floor and with one end fixed against thefloor is leaving a gap of maximum 2 mm

per every 2 m batten length, i.e. a battenwith a length of 3.9 m is accepted to have awarp corresponding to maximum 4 mm gap(at the other end)

SUBFLOOR I I

Straightedge, 2 m

Level deviation accepted value

Max. 5 mmRetholt, 2 m

ITSideways deviation accepted value

Batten

Max. 2 mm

Figure 13 Tolerances accepted on battens

Knot groupa+b+c=½ d

d or 150 mm

Single knot



The battens must be of a qualitycorresponding to the grading criteria appliedin grading class T1. Consequently, singleknots are only allowed to constitute 1/3 of the cross sectional area and groups of knotsonly ¼ of the cross sectional area, see

figure 14.The best result is achieved when themoisture content corresponds to that of the flooring boards. This will effectivelyreduce squeaking problems.

The moisture content in the battens mustnever exceed 12 % i.e. the average of moisture testing results should be maximum12 %, and any single testing result must notexceed 14 %, see Appendix: Acceptancecheck.

Packing pieces and cradle systemsMaterials used to chock up battens could be:

(see figure 15)Plywood blocks, minimum 100 cm 2,for example 100 x 100 mm or 80 x125 mm

Chip board blocks, minimum 100cm2, for example 100 x 100 mm or 80x 125 mm

Hard or soft wood fibre board blocksminimum 100 cm 2, for example 100 x100 mm or 80 x 125 mmPlastic wedges or plastic towersPlastic or metal bases including accessoryadjustable sub-system.

When a higher block is required it is possible to use plastic towers (allows for more deflection), plastic or metal bases or asupport made of fixed masonry or castconcrete blocks (no deflection) upon whichthe final blocking up is placed.

Plastic wedges used as packing piecesshall have a documented approvalconcerning life expectancy and loadcarrying capacity ensuring long termdurability. Exposure to excessive heating,for example from close contact with heating

pipes, may reduce life expectancy

considerably.Plastic wedges of unknown origin andquality may decompose over time resultingin the settling of the floor which again mayresult in the need to substitute or relay thefloor.

12 SUBFLOOR

Figure 15 M aterials used as packing pieces andcradle systems: Plywood blocks (1), hard fibre

board blocks (2), chipboard blocks(3), soft fibre board blocks (4), plastic wedges (5), wooden

wedges (6), plastic tower cradles (7) and adjustablecradle system with plastic or metal bases (8 and 9).



Soft blocksSoft blocks used in order to reduce theeffect of impact sound shall be made of 12-13 mm thick porous wood fibre boards witha density of 225-300 kg/m 3 adhered to a

pressure equalizing board made of minimum12 mm plywood. The blocks shall have anarea of minimum 100 cm 2 for example 100 x100 mm, see figure 16.

The use of soft blocks with a smaller areaor a lower density may result in the settlingof the floor during use.

Bitumen feltBitumen felt is used under blocks in order to establish a sturdy underlay protecting thedpc (and being diffusion tight at the sametime). It is recommended to use pieces of approximately 20 x 20 cm, see figure 16.

Figure 16 Soft blocks made of 12-13 mm porouswood fibre board adhered to minimum 12 mm

plywoo d plac ed on bitu men felt .

Bituminous felt may be used asdpc under floating or glued floors. Thequality shall be PF 2000 (no sand finish) seefigure 18.

Insulation materialsInsulation materials are used in the floor construction in order to improve soundor heat insulation, see figure 17.

In batten or joist constructions it isrecommended to insert 100 mm softmineral wool between battens or joists inorder to absorb sound.

In floating floor constructions thefunction of the insulation is to prevent thetransmission of impact sound from the floor to the structural floor and at the same timeto transfer load. With respect to impactsound it is recommend to use an insulationmaterial with springy characteristicswhereas considerations to strength andstability requires the use of a rigidinsulation material. The required rigidity of the insulation material is determined on the

bases of the expected load, the thickness of the insulation and the type of floor material.

SUBFLOOR 13

Figure 17 Insulation materialsused for floating floors.



Figure 18 Examples of moisture barriersTop: (1) Combination: Plastic, felt and cardboardMiddle: (2) PVC foil in different thicknesses/qualities.Bottom: (3) Bitumen felt PF 2000, no sand finish.

Moisture barriersPlastic foils used as moisture barriers must

be at least 0.20 mm PE-foil (Polyethylen)in order to have sufficient strenght towithstand strain during the construction

period. Only foils with a documenteddiffusion tightness and durability should beused, for example complying with SPSVerksnorm 200/2001 (German standard).

Caution should be taken that the foil isnot perfurated by a pointed concretesurface.

Plast foil is a good sliding layer for floating floors, particularly so when used intwo layers or combined with flooringcardboard or similar products, see figure 18.

Moisture barriers can also be carried out

using bituminous felt, epoxy or specialglues:

Bitumen felt glued to the subfloor, see page 21.

Cast asphalt with a thickness of 20 mm.Epoxy is applied in thin layers one atthe timeAn impartial documentation verifyingthat the product is efficient as a moisture

barrier must be available. When applyingthe prescribed thickness shall be observedas experience shows that the moisture

barring ability is being drastically reducedwhen the layer thickness is too small - thismay case subsequent damage to thewooden floor.Special glues - MS-glues are primarilyfunctioning as a barrier retardingmoisture penetration and only to alimited extend as an effective moisture

barrier, see page 20.

14 SUBFLOOR



Flooring cardboardFlooring cardboard is used as underlay for flooring planks, parquet and flooring

panels in order to reduce clatter. Flooringcardboard is a non impregnated cardboardwith a weight of roughly 500 g/m 2,seefigure 19.

Foam plastic, cork sheet, or similar Foam plastic, cork sheet or similar products

placed loosely under wooden floors serveas a pressure equalizer and sliding layer atthe same time. The products also contributeto improving acoustics as they preventclattering between floor and underlay andreduce impact sound. Some products alsofunction as a moisture barrier eliminating the

need for an additioanl moisture barrier, seefigure 19.In order to secure that the products

possess relevant characteristics anddurability, only such products recommended

by the floor manufacturer should be used.

Rubber cork/cork rubber Sheet rubber cork contributes to thereduction of impact sound and to improvedflexibility in the floor. The effect dependson the thickness and composition of the

product, see figure 19.

Figure 19 Clatter impact sound reducing materialsfor example flooring cardboard (1), flooring felt (2),foam plastic (3), plastic granulate (4), cork dustsheet (5), cork sheet (6) and rubbe cork (7).

SUBFLOOR 15



Stuctural joistsStructural joists functioning as underlay for suspended floors shall be aligned forming a

plane surface or a plane surface established by the application of an additional plank/batten on top of or on the side of thestructural joists. Additional planks/battensshall have a minimum width of 45 mm inoder to avoid splitting when nailing/screwingthe floor.

Joists should be chosen with considerationto the risk of warping; i.e. with minimumtendency to warping, The need to reestablisha plane surface may be minimized by usinglaminated wooden joists (or HQL).

The best result is achieved when themoisture content in the joists corresponds tothat of the flooring boards. In case themoisture content in the joists is too highthere is a risk of floor settlement due toshrinkage when the timber dries. The taller the joist is the bigger is the problem. Themoisture content in th joists must not exceed13 %, i.e. the average of moisture testingresults should be maximum 13 %, and anysingle testing result must not exceed 15 %.

see Appendix: Acceptance check.

Concrete slabWhen a concrete slab is used as underlay for nailed or glued wooden floors it is requiredto level the surface using a self levelingcompound, a skimming compound or ascreed.

When wooden floors are glued to aconcrete slab the surface must be cleaned of concrete slur as the slur layer does not havesuffient strength to absorb tension that mayoccur as a consequence of moisturemovements in wooden floors

For further information concerning concreteslabs reference is made to Concrte floor constructions elaborated by the CementManufacturers (Cementfa-brikkernestekniske Oplysningskontor), 1994concerning workmanship concrete floorsand also GSO Flooring Facts (GSOGulvfacta) concerning leveling of floors.

ScreedsScreeds are used for the leveling of concrete slabs. Screeds may be based oncement, anhydrite or magnesit. Screeds canalso be made from cast asphalt which at thesame time will function as an effectivemoisture barrier.

Screeds are normally laid in thicknessesof + 15 mm. The properties of the screeddepend on type and composition. In casethe floor is a non-suspended wooden floor itis in most cases necessary to skim thesurface in order to obtain a sufficiently levelsurface.

For further information on screedsreference is made to GSO Flooring Facts(GSO gulvfakta).

SandSand used as underlay for floating floorsshall be well graded, kiln dried quarts sand.All fractions of the grain curve must berepresented in order to secure sufficient

packing after application and compression.

16 SUBFLOOR



FIXINGS

A varyity of fixings such as nails, screws,glue and clips are used when laying woodenfloors.

Nails, screws and staplesPlanks in suspended floors are fixed to

battens or joists using square nails, pinnails, screws, air gun nails or staples.

Wooden floors may be nailed from aboveor using hidden (secret) nailing.When air gun nails are used only hidden nailing isrecommended. Nailing from above ensuresa better fixing of individual planks as itallows for dimensional changes across the

plank.

On the other hand, hidden (secret) nailinghas the advantage that planks are pushedtogether (manual nailing), see figure 20,

page 18.When nailing hardwoods it is required to

prebore before nailing or screwing. The drillused for preboring must be slightly smaller in diameter than the used nails or screws, for example a 3.5 mm drill used for 4.2 mmscrews.

Table 2 indicates dimensions of nails andscrews to be used for different plank thicknesses. As battens and joists do expandand contract in accordance with humidity, itis not recommended to use fixings longer than those indicated in the table as doing somay increase the probability of squeaking.

Table 2 Recommended dimensions on nails and screws for flooring planks laid on battens or joists. Thesame screw dimensions may be used when fixing flooring boards to an underlay made of chipboard, planks or the like. Hot dip galvanized nails provide the best grip in wood. Be careful not to use nails or screws longer thatn those recommende as doing so may increase the probability of squeaking when the battens or joistsexpand and contract. For direct fixing in concrete it is recommende to use special screws, for example Monta-flex. When in doubt, always consult the supplier of nails and screws.

Nails Air gun nails ScrewsPlank thicknessin mm -nails/finishing

nailsStaples T-pin nails Twisted

nailsMonta-flexscrews

Chipboardscrews

12-15 1.8x40 M-32 mm 1) l.8x38 1)

F-14 2.0x38 2)

F-14 2.0x45 3)

4.2x45

20-23 Solid pine/spruce

2.8x65 2,5x65 1) TS 2,3x65 2) 3)

4030-2½" 2)4.2x45 5.0x45

Solidhardwoodd;

2.8x65 2.5x65 1)

4030-2½ 2)4.2x45 5.0x45

Wood veneer flooring boards

2.5x55 N-50 mm 1)

S-16 50 2)TS 2.3 x 65 2) 4.2x45 5.0x45

25-26 3.1x80 4.2x45 5.0x5528-30 3.4x90 4.2x55 5.0x75

35 3.8x100 4.2x75 5.0x751) Manufacturer:Ottensten

2) Manufacturer:Unimerco

3)For planks with a width between 100 mmand 150 mm

16 Fixings



NailsChoice of nail type depends on wood speciesand floor type. As a rule of thumb squarenails are used for manual nailing and twistednails are used for air gun nailing insoftwoods such as pine and spruce. Staplesshould only be used when recommended bythe floor manufacturer.

When fixing hard woods such as oak or beech, pin nails are used for manual nailingand T-pin nails for air gun fixing, see figures21 and 22.

Nailing should only be carried out usinghot dip galvanized nails as experince showsthat they have the best withdrawalresistance. Also, contrary to bare steel nails,galvanized nails do not cause discolourationwhich reduces such risk in light coloureddelicate planks.

Traditionally wooden floors are handnailed, and this method is still consideredthe safest particularly so when laying solid

planks in large dimensions in order tosecure that the planks are pushed properlytogether and are securely fixed to

battens/joists.

Figure 20 Fixing methods using nails or screws

Air gun nailing is used for certain flooring boards but should only be used whenrecommended by the floor manufacturer.When nailing with an air gun it isimportant to press the flooring materialhard agains the underlay in order to secure

proper fixing. Pressing with the air gunitself is in most cases insufficient.

Staples T-nails

Figure 21 Nail type for hand nail ingTwisted nails

Figure 22 Nai l types us ed for air gun .

18 FIXINGS

Nailed from above Hidden (secret ) nailin g

Finishingnails

nails Flooring nails



ScrewsThe choice of screws depends on thescrewing principle adopted (from above or hidden). When screwing from above, ø 5mm partially threaded chipboard screws areused. This is a type of screw which has nothread immediately below the head andthus ensuring a better fit of the flooring

plank against the underlay. When applyinghidden screwing, special screws as for example Monta-flex are used. This screwhas a high withdrawal resistance in wood,wooden boards and in concrete underlay,see figure 23.

When screwing from above it isrecommended to prebore a minimum 6 mmdeep hole using a 10 or 15 mm drill in order to countersink the screws. Subsequently theholes are covered using a wooden plugmade of offcuts using a wood plug cutter,see figure 24. The plugs are glued fixing thegrains in the same direction as the grains inthe flooring planks. When the glue is drythe plugs are cut off flush with the over sideand the planks are sanded.

Wooden underlayPlanks fixed on structural sub floors made of chipboard, plywood or wooden boards may

be screw fixed provided the sub floor lays on beams or joists. The sub floor must havesufficient thickness to secure satisfactoryadherence.

Figure 24 Secret fixing from above usingchipboard screws covered with a wooden plug.

In sub floors made of chipboard the screwsmust be sufficiently long to penetrate thechipboard. Chipboard screws or specialscrews like for example Plata-flex areused.

The nailing and screwing of floatingfloors chould only be carried out whenadvised by the floor manufacturer.

When using secret screwing it is arequirement that the flooring plankshave thickness of minimum 12 mm. f

Concrete underlaySpecial screws for example Monta-flex, areused when fixing directly on concrete.Preboring is required using a drill with adiameter slightly smaller than the screwdiameter, for example a 3.5 mm drill for 4.5 mm screws. The screw may be fixeddirectly into the prebored hole without theuse of plugs.

Repairing squeaking floorsExisting squeaking floors laying on battensor joists may be nailed from above usingspecial nails such as annular ring nails or twisted flooring for example 3.5 x 55 mmfor 20-22 flooring planks and 3.5x 65 mmnails for 25-28 mm flooring planks.

Figure 23 Screw types

Fixings 19

Wooden plug

Floor

Screw

Batten

Chipboardscrews

Monta-Flex

Plata-Flex



GlueGlues used for the adherence of or gluingtogether of flooring boards must chosenconsulting the recommendations issued bythe floor manufacturer in order to ensurethat the glue is compatible with the woodenfloor and the underlay as well as being ableto resist whatever loads may occur. Thesurfaced to be glued must be clean, dry andglueable. Manufacturer s instructionsconcerning priming, consumption,application etc. must be complied with inorder to secure a good result.

Glui ng enti re face When gluing the entire face of a woodenfloor it is required that the underlay is level,i.e. level deviations maximum ± 2 mmalong a 2 m straightedge and withoutcraters or pointed edges in order to secure

proper contact between materials.Levelness of surfaces is described in detailin Appendix: Levelness

The glue to be used is so-called parquetglue, either in the form of water baseddispersion glue or MS glue, i.e. glue basedon Modified Silicone. The latter is moreexpensive but has the advantage that it isfree of water and to a certain extendfunctions as a moisture barrier, see below.The glue must not be too thin.

Wooden floors must not be glued until theresidual moisture content in the underlay issufficiently low, or until an effectivemoisture barrier has been inserted, see moreabout moisture barriers on page 14.

When using dispersion glues the residualmoisture content must not exceed 65%relative humidity, whereas the similar limitfor MS glues is 85% residual moisturecontent (does depend on glue brand),measured at temperatures between 17 and25 °C.

The adherence of wooden floors shall take place within a certain period of time, the so-called open time, in order to ensuremaximum bonding. The fixing time isnormally approximately 15 minutes, butdepends on the materials to be glued and onmoisture and temperature conditions in theroom.

The fixing time is short for materials with ahigh absorption rate such as particle boardand certain softwoods whereas materialslike bitumen cardboard and rubber cork allow for a longer fixing time. Whenapplying glue it is advisable to consider theglue s open time in order to ensure thatlaying may be carried out within the limitof the open time .

Fl oor glue requir ements From a wood technical viewpoint the glueshould have the below listed properties:

Low absolute water content in order toavoid deformation of wooden floor materials as a result of unilateralmoisture exposure on the underside.Ability to fill in such a way that contactcan be established between glue and theflooring material even in unfavourable

situations, for example when there aresmall cavities in the underlay.Rapid fixation, maintaining thestave/plank in a fixed position in glue

jointElasticity allowing the glue to absorbwhatever movements there may occur inthe glue jointSufficient strength

When gluing under difficult circumstances,for example on surfaces with littleabsorption or the gluing of floor elements inlarge dimensions (planks) it is advisable to

use one or two component glues without water. The use of such glues may, however,cause work environmental problems as the

bonding agent in most cases is based on polyurethane.

Glu i ng tongue and groove The purpose of gluing the tongue andgroove joint in floating floors is primarily toensure that movement is being transferredfrom board to board (by creating a coherentfloor surface). In this way the individualstaves or boards function together, andvertical forces may be accepted withoutunacceptable deflection. Further, the glued

joint may serve to prevent the penetration of water when cleaning the floor.

20 FIXINGS



PVA glue is normally used when gluingtongue and groove joints. In order toensure maximum strength of the joint it isimperative to choose a glue which iscompatible with the wood species and alsoto ensure that the glue fills and is water resistant in order to prevent damagescaused by surface treatment and cleaning.The glue type normally used is a so-called

winter glue (class D3).

Gluing bitumen cardboard When bitumen cardboard is used as a

moisture barrier it may be glued to theunderlaying concrete slab using parquet glueor a dispersion glue. When doing so theresidual moisture content in the concretemust not exceed 85% (RH) and capillary riseof ground moisture must not occur.

ClipsSome flooring boards may be joined by theuse of steel clips. Clips are used for floating floors. The clips are slotted into amilled groove at the backside of theflooring board and connect twoneighbouring boards. In doing so, it isensured that the boards can moveindividually in the horizontal directionwithout being pushed apart and the totalmovement of the floor is reduced, seefigure 25.

Click-jointsSpecially designed for floating floors are anumber of flooring boards with a self locking tongue and groove. When the

boards are laid they are clicked together and require no further fixing, see figure 25.

Figure 25 As an alternative to gluing tongue andgroove, floating floors may be laid usingmechanical joints in the form of steel clips(2) or click-joints(1).

FIXINGS 21



W OOD AND

MOISTURE

Wood shrinks and expands in accordancewith air humidity and temperature. In order to get a good result, it is important toconsider this particular characteristic whendesigning and constructing wooden floors.

Why does wood shrink?The cellular walls in the living tree aresaturated with water, and the cell cavitiesare also filled with water. Wood shrinkswhen the water confined in the cellular walls dries out. The cellulose in thecellular walls has the property that itabsorbs water from the air and expands

when the air is moist and contracts when theair is dry. Hence, the moisture content anddimension of the wood will always adjust to

be in equilibrium with the relative humidityand temperature of the surrounding air, seefigure 26.

The shrinking and expansion of wood inaccordance with variations in air humidity isthe reason why wooden floors shall be laidkeeping a distance to surrounding buildingcomponents allowing for expansion whenthe wood is exposed to moisture. This alsoimplies the need to lay wooden floors aslate as possible in the building processwaiting for the building to dry out and thusreducing the amount of moisture present.See section describing The building site and requirements related to moisture.

Relative air humidity (per cent) Scrinkage (per cent) fromfreshly cut

Figure 26 Graphic illustration of equilibrium moisture content (left) shows the connection between relativeair humidity and moisture content in wood at approximately 20 °C, and the graph to the right shows calculationof shrinkage when the changing equilibrium moisture content.

22 WOOD AND MOISTURE

Tem[ cratu: Fyr

] ;are f ir vs.« mpe; egret iKonstructionstra;

Ovm 0rrin; pak 'icvet

UienlljTS___ o\er-d; ikket

Lejl ghed ;vis (ipvar- " med; run

C'entral-opvamederim

Raiialsvinc Tangenlials

Dry rot danger

Structuraltimber

Temperature approximately 20 oC

Kiln drying

required Outdoor coveredconstructions

Occationallyheated rooms

Rooms withcentral heating

Pine

Radialshrinkage

Tangentialshrinkage



How does wood shrink?All fibres in a freshly cut tree are water saturated. Later, as the wood dries there will

be dimensional changes (shrinkage) more or less corresponding to the reduction of water.Similarly, wood will expand when exposedto moisture. Expansion and contraction arecharacterized by taking place in threedominant directions, see figure 27.

Tangentially along the annular rings(circular in the trunk)

Radially - Perpendicular to the annualrings (along pith rays)

Axially- Along fibres (longitudinaldirection)

Figure 27 The three dominant directions for shrinkage and expansion of wood

Normally, the tangential shrinkage isapproximately twice as big as the radialshrinkage. The axial shrinkage is onlycorresponding to somewhere between onetenth and one twentieth of the radialshrinkage and for the same reason it may

be disregarded in most cases.Items with pith are subject to one or

shrinkage splits extending from surface to pith and as a consequence they are not fit to be used for flooring, see figuer 28.

There may be considerable differences between the density of the bottom part andthe top part of a trunk and thereby also bigvariation in shrinkage and moistureconditions.

Shrinkage split

Figure 28 Items with pith are subject toshrinkage splits depending on the position of the pith in the board.

How much does wood shrink?It is often necessary to be able to calculate

by how much a certain dimnesion ischanged as a result of varying moisturecontent in the wood (which, as explainedabove, will vary in accordance withvarying air humidity). As a realisticaverage, which may be applied to a number of commonly used wood species, it may beassumed, that the change of 1 % in woodmoisture content results in a dimensionalshrinkage of approximately 0.15 % (1.5mm/m) radially, and approximately 0.3 %(3.0 mm/m) tangentially. When calcualtingexpansion the same values may be applied.

Hvis trasemnet er planskaret eller spejl-skaret, se figur 29, kan de to svindprocenter anvendes direkte. I praksis vil emnerne oftevasre en mellemting mellem de ovennaevnteopskaeringer, derfor kan der anvendes etmiddeltal pa 0,22 % (2,2 mm/m).

WOOD AND MOISTURE 23

Shrinkage split

Pith

Pith

Radially

Tangentially

Radial cuts

Figur 29 Shrinkage and expansion of wooddepends on conversion principle applied/annualring position.

Axially

Tangentialconversion



How moisture influences woodenfloorsWhen choosing wooden floor type and alsowhen constructing the floor it is importantto consider the inevitable dimensionalchanges caused by seasonal variations inair humidity, see figure 30.

It is not possible to avoid joints betweenflooring boards, but it is possible to predictthe size of future joints simply by choosingthe right floor. In this context the term jointis used to describe the gap betweenindividual boards or staves in the floor.

The size of the joint may be reduced asfollows:

Use narrow boards in stead of wide boards because the size of the joint corresponds to board width.Choose products with small dimensionalchanges as a consequence of changed air humidity.Control climate, for example by the use of air humidifiers in office buildings duringthe winter in order to avoid the drying outof wood.Avoid the use of floor heating systems andradiation heating systems placed in theceiling.

Grams of water per m 3 air

Jan . Mar. May Jul . Sep . Nov.Feb. Apr. Jun . Aug. Oct. Dec.

Figure 30 Typical variation in the relative humidity(RH) inside and outside du ring the year. The relativehumidity is at its maximum inside from August toOctober, and at its lowest from December to March .(SBI direction 178).The RH in office buildings andthe like is often considerably lower that indicated inthe graph.

10-board measurementWhen laying a wooden floor it is importantto ensure that the floor can absorbmovements caused by moisture. This isoften done by use of the so-called 10-boardmeasurement.The10-board measurement is defined as theexpected width of 10 boards when exposedto maximum moisture. This is typically inthe autumn where an average of 13 %moisture content may be expected in theflooring boards. When laying the floor withlower moisture content, for example kilndried to 8 % it must be ensured that a small

joint is established between the boards/staves for example by placing thinspacers between the boards. The 10-boardmeasurement shall be controlled at regular intervals during the laying of the floor.

Wood veneer flooring boards and softwood flooring boards, for example pine, arenormally not laid observing the 10-boardmeasurement.

The 10-board measurement depends on:

Width of boardsMaximum expected air humidity.Wood species (expected change in board

width)Annular ring orientation (radial or

tangential conversion)

The 10-board measurement is mainly usedwhen laying floors type:

Hardwood parquet boards (nailed)Solid parquet staves with T&G glued tothe sub floor.Parquet staves (nailed)

SpacersUntil recently it has been common practiceto observe compliance with the 10-boardmeasurement simply by basing the laying onexperience whereby the contractor wouldcheck the prescribed 10-board measurementat regular intervals during laying procedure.

In order to ensure uniform spacing it isrecommended to use so-called spacers, i.e.small pieces of plastic with a thicknesscorresponding exactly to the joint required inorder to comply with the prescribed 10-boardmeasurement. The use of such spacers willmake the constant checking procedureredundant as the spacers will ensurecompliance with the prescribed 10-boardmeasurement.

24 WOOD AND MOISTURE

RH %

R H o u t

RH in

IN

OUT



Examples

WOOD AND MOISTURE 25

Some examples showing how muchmoisture influences dimensionalchanges of a wooden floor.

Example 1When a flooring board has been storedfor some time at approximately 20°C andexposed to approximately 78 % RH it willhave a moisture content of approximately16 %. If the RH is changed to 40 % andthe temperature is maintained at 20°C thewood will discharge water to the air andthe moisture content will adjust toapproximately 8 %, see figure 26. Thus,the moisture content will be reduced by8 % which will result in the followingshrinkage:

Tangential shrinkage: 0.30 x 8 = 2.4 %Radial shrinkage 0.15x8 = 1.2 %

Suppose the board is cut tangentially witha width of 100 mm and 16 % moisturecontent, it will, at 8% moisture contenthave a width of: 100 - (0.3 % x 8 x 100) =97.6 mm.

Suppose the board is radially cut, thewidth will be: 100 - (0.15 % x8 x 100) =98.8 mm.Suppose the board is cut somewhere in

between radially and tangentially thewidth will be: 100 - (0.22 % x8 x 100) =

98.2 mm.For wood species (or products) withsmall dimensional changes caused bymoisture variations, the shrinkage may

be reduced by 50 %, whereas theshrinkage in wood species with larger dimensional changes may be increased

by 50 %.The shrinkage in the longitudinal

direction is normally less then one tenthof width shrinkage.

Example 2A traditional wooden floor has 18 boards

per 2 m. The boards are laid withoutspacing. After some month the spaces

between the boards will vary in size from0 to 5 mm.

The total width of the17 spaces has beenmeasured by the use of feeler gauge andis 48 mm which corresponds to 2.4 %across the 2 m floor.

An average shrinkage of 0.22 % for every 1 % change in moisture contentwill result in (2.4 %: 0.22 %) = 11 %change in moisture content of the boardsin order to cause a shrinkage of 2.4 %. Asthe actual moisture content is measuredto 7 % it can be concluded that themoisture content was 7 + 11 = 18 %when the boards were laid.

Example 3A floor consists of 100 mm wide floor

boards with a moisture content of 8 %.The floor is laid in a room with 23 °Cand 40 % RH, which corresponds toequilibrium moisture content in of 8% inthe wood. 10 boards will under theseconditions give a width of 1000 mm,

provided they are laid without spaces.It is, however, assumed that the RH in

the room will increase to 65-70 % duringthe summer period corresponding to amoisture content of 13 % in the wood.Exposed to these conditions each boardwill expand by (0.22 % x 5 % x 100 mm)= 1.1 mm (cf. example 1). In order toallow for this expansion it is required tolay the boards with a spacing of 1.1 mm

per board, i.e. 10 boards will require atotal width of (1000 mm + 10 x 1.1 mm)= 1011 mm, which in this case will bethe 10-board measurement..

During winter, the temperature may be23 °C and the RH 25 % corresponding to adrop in wood moisture content to 6 %.Using summer conditions a starting pointthis means that a board during the driest

period will shrink approximately (0.22 %x (13 - 6) % x 100) = 1.5 mm. It can thus

be expected that a floor laid under abovementioned assumptions will have 1.5 mmwide joints between the boards duringthe driest period.



Moisture protection -requirements

Design and construction assumptions

Avoiding excessive exposure to moisture or exposure to moisture during a longer periodare preconditions for the use of wood in floor constructions. Neither must the floor beexposed to excessive drying out. Suchexposures may result in the risk of rot or dryrot when the moisture content exceeds 20 %(weight), and it may also cause undesirabledimensional changes and deformations.

In the subsequent section it will bedemonstrated how to construct woodenfloors avoiding moisture problems. In office

buildings, where the production of moistureis normally at a minimum, there is a risk of extreme drying out during periods with frost.This may result in shrinkage and as result of this in larger cracks in wooden floors,

particularly so in floors constituting large planes without or with limited possibilitiesfor movement. In some cases it may benecessary to use humidification during thecoldest and driest periods of the year in order to avoid damages.

In order to ensure correct construction of wooden floors, particularly with respect tomoisture, it is advisable to follow theguidelines laid down in SBI -Direction 178:

Moisture insulation of buildings. See alsoSBI-Directions 184: Heat insulation of buildings and 189: Single family houses insulation, moisture protection etc. offeringconcrete examples of constructions meetingcurrent requirement in terms of moisture

protection and heat insulation.

Outside the building The terrain must slope away from the buildingin order to allow for the effective drainingaway of surface water. In flat terrain theslope shall be minimum 1:50. In slopingterrain it is required to level the ground on the

side of the building with the highest terrainand it is recommended to establish anintercepting drain at the intersection betweenthe naturally sloping terrain and the adjusted.

Sloping terrain

Figure 31 Adjustment of site profile ensures theleading away of surface water and drainage iscarried out to the extend necessary.

Paved terraces shall be established with aminimum slope of 1:40 in order to preservethe slope also in the event where the

pavement settles, see figure 31.

Ground supported floor When constructing a ground supported floor,measures must be taken to prevent theabsorption of ground moisture. This may be

done by the insertion of a capillary breakinglayer. Residuous moisture in the concreteslab must be prevented from entering thewooden floor by the insertion of a dpc on topof the slab. Joints in this dpc must have anoverlap of minimum 200 mm. The jointsshould also be additionally secured by theuse of tape or butyl rubber sealant strip.The dpc is lead close to the wall and anairtight joint is established between the dpcand the dpm in the wall (if any). This alsosecures against the penetration of radon, seefigure 32.

In order to avoid condensation of

moist air from the room on the top sideof the dpc, it is required to place at least

26 MOISTURE PROTECTION - REQUIREMENTS

Perimeter drain

Flat terrain

Intercepting drain



Figure 32 The placing of dpc and dpm inconstructions with floating floors on groundsupported slab.

Figure 33 The placing of dpc, dp m and insulationin constructions with suspended floors on flooring

battens on g roun d supported slab.

half the insulation under the dpc. In practice this is most often done by placinghalf the insulation under the concrete slab,see figure 33.

When carrying out renovation works, it isoften only possible to place insulation ontop of the dpc. In such instances it isrecommended to use maximum 50 mminsulation in order to avoid the risk of condensation on the topside. Requiredadditional insulation will, in this case, haveto be carried out as foundation insulation.

Heating pipes under wooden floors must be insulated separately and effectively inorder to avoid the drying out of flooring

boards. Also, measures should be taken to place the pipes on the warm side of theinsulation.

When a diffusion tight floor covering (for example vinyl or linoleum) is used on asuspended floor on flooring battens in order to allow the floor construction to adjust tothe humidity of the air in the room. In thiscase a cavity of minimum 30 mm must beestablished on top of the insulation materialin order to allow the room air to ventilate theunderside of the floor.

Figure 34 Establishing additional ventilation infloors on flooring battens covered with a diffusiontight floor covering (for example vinyl or linoleum).

MOISTURE PROTECTION - REQUIREMENTS 27

dpm

Wooden floor

dpc

Insulation

dpm

Wooden floordpc

Insulation

Minimum slope

Ventilation

Diffusion tightfloor covering'

Insulation

Minimumslope

Cut outs inskirting board



Ground supported floor in unheated buildingsThe temperature in unheated buildings, suchas holiday cottages, will, during winter, behigher in the ground under the building thanit is inside the building. Hence, the moistureflow will, during winter, go from the groundthrough the ground supported floor and intothe house. In such buildings it is importantto establish the moisture barrier (dpc)correctly. No moisture sensitive materialsmust be placed under the dpc and joints inthe dpc as well as joints to other buildingcomponents must be airtight in order toavoid the risk of condensation on theunderside of a diffusion tight layer. This isalso the reason why the use of diffusion tightfloor coverings should be avoided inunheated or occasionally heated buildingswith a ground supported floor. G

Crawl spacesIn crawl space decks consisting of woodenfloors on joists it is particularly important tomaintain the humidity of the air in the crawlspavc at the lowest level possible. It isrecommended to establish a dpc at the

bottom of the crawl space in order to preventthe ingress of moisture from the ground

below. It is also required to establishsufficient ventilation. Figure 35 shows thesize of and the placing of necessaryventilation openings.In order to prevent the ingress of radon it isrecommended to place a dpm under thewooden floor.

BasementsThere is always a risk connected to thelaying of wooden floors in basements. Onething is certain: If the basement is not drythe wooden floor will not last!! If moisture is

present, the floor will be exposed toexcessive dimensional changes. Beforelaying wooden floors in new buildings allmoisture must be ventilated away until the

basement is sufficiently dry. In unheated basements the RH will, especially duringsummer, reach 90 % which is too high for

the use of wooden floors. A modest heatingof the basement may reduce the RH to 75%during summer provided there is nomoisture penetration through leakages in

Figure 35 The placing of dpc, dp m and ventilationopenings in constructions with wooden floors on

joist s (c rawl space deck) .

external walls or capillary rise of groundmoisture.

The external basement wall shall bedrained and the drain must be connected tothe perimeter drain in order to prevent thelocal occurrence of water pressure againstthe external wall. The outer side of the

basement external wall shall have a doublecoating of liquid bitumen applied on top of arendered or rough cast surface or by the useof specially designed PVC drainage sheeting

preventing the penetration of moisture.With respect to moisture it is advisable to

carry out heat insulation on the outer sideof the wall and on the outer side of possibledrainage sheeting.

Under the basement floor it is required toestablish a capillary breaking layer

preventing the absorption of moisture fromthe ground. The best solution is to place theheat insulation under the concrete slab. Thisinsulation may depending on the choice of materials be carried out as a combinedheat insulating and capillary breaking layer,see figure 36.

Provided the basement construction iscarried out along the above describedrecommendations and, provided it isheated, it is possible to lay a wooden floor following the same guidelines as thoseapplicable to a normal ground supportedfloor. It is required to place a dpm on theconcrete slab before laying the woodenfloor. Joints in the dpm shall overlap byminimum 200 mm and the joint betweendpm and wall shall be airtight.

28 MOISTURE PROTECTION - REQUIREMENTS

DpmWooden floor Insulation

DpcVentilation

Dpc

Slopeminimum1:50



Figure 36 The placing of dpc, dpm and insulationin constructions with a floating wooden floor onstorey partitions and on ground supported floorsin basements.

When renovating old houses it is often awish to establish wooden floors. In suchcases it is required to carry out a moistureinsulation of the constructions. The floor

construction principles are similar to thoseused in new buildings. In case the roomheight is low, it is possible to use a floatingfloor construction with a moisture and

pressure resistant insulation as the loadcarrying underlay. The dpc can be placed

between insulation and wooden floor or under the insulation (in case the quality of the insulation is inferior to or equals 50 mmmineral wool lambda class 39). For further information concerning the renovation of old basements, reference is made to SBI-

Direction 178 .

Storey partitionsIn order to eliminate the risk of problemsoriginating from construction moisture it isrecommended to place a dpc on top of newconcrete or light weight concrete deck storey partitions. It is not required to place adpc on top of existing and dry deck constructions.

Moisture requirements on the buildingsite.The dimension of wood depends onmoisture content which again depends onthe relative humidity (RH) and temperatureof the surroundings. As the relativehumidity changes with the seasons and alsowith the use of the room so will thedimensions of the wood change. It is veryimportant to consider this aspect whendesigning and laying wooden floors.

In order to avoid unnecessary moisteningit is important to lay the floors as late as

possible in the building process. The building shall be closed dry and heated before laying the floor. All such works asmay cause the generation of moisture, for example plastering and basic paint work shall be terminated before the flooring starts.The RH in the building shall be inequilibrium with normal RH for the season,i.e. 35-65 % relative humidity atapproximately 20°C.

When concrete or light weight concreteelements are used it will, in most cases, benecessary to wait for a couple of months

before laying the wooden floor. If necessary, it may be required to usedehumidifiers. Before laying wooden floorson new concrete or light weight concretedecks it is required to measure the moisturecontent in the deck, see Appendix:

Measuring moisture content in concrete.Insulation materials etc. shall be dry. In

case blocking up has been carried out usingconcrete or brickwork such elements must

be cured and dry.In case the building has not been properly

dried out, the relative humidity will be veryhigh and the wood will expand after laying and later, when the wood dries out, the joints between the boards will be verywide. In case there is too little spacearound the floor the expansion may causethe floor to pop up or in the worst case to

push out surrounding walls.

MOISTURE PROTECTION - REQUIREMENTS 29

Dpm

Insulation

Wooden floor

- Dpc

Wooden floor

Dpc

Insulation

Drain

Slope,minimum1:50

Insulationand drain



When investigating the moisture conditions before laying wooden floors on concrete it isnot suficient only to measure the relativehumidity of the air but it is also required tomeasure the moisture content in theconcrete. The reason why is that ventilationmay reduce the relative humidity of the air without reducing the moisture content in theconcrete.

In case wooden floors are to be used under conditions where it is only required to secureagainst moderate construction moisture fromunderlaying concrete, i.e. a pore moisturecontent of 60-90 % RH, it is possible to avoidmoistening the wood by using a PE-foilminimum 0.20 mm thick. This dpc shall belaid with minimum 200 mm overlap on top of the moist concrete before laying the woodenfloor.

Flooring materials - moisturerequirementsFlooring and parquet boards and are normallysupplied kiln dried and wrapped in a strongPE-foil with a moisture content of 8 ± 2 %.2/3 of the lot should have moisture content

between 7 and 9 %. The moisture content in joists, flooring battens and blocks should, asfar as possible, correspond to the moisturecontent in the supplied floor.

At the point of laying the average moisturecontent in flooring battens should not exceed12 % and in joists it should not exceed 13 %.In practice this means that the average valueof 12 % (13 %) must be complied with andno single values of moisture content inexcess of 14 % (for battens) and 15 % (for

joists) are accepted see Appendix: Acceptance check.

In cases where it is not possible to get asupply of flooring materials with correctmoisture content, it is imperative to deliver the flooring materials well in advanceallowing sufficient time for acclimatization,i.e. to attain equilibrium with the temperatureand moisture conditions in the room beforethe actual laying. This process may takeseveral weeks even when the boards arestacked. Laying a wooden floor with

excessive moisture content may result in theoccurrence of larger joints between the

boards when the wood dries out.

30 MOISTURE PROTECTION – REQUIREMENTS

Check list – laying wooden floors The relative humidity in the buildingshall be between 35 and 65 %,(depending on the season) and thetemperature approximately 20°C.The building must be closed and theheating system operational and in use.The moisture content in concrete andlight weight concrete shall be inequilibrium with the relative humidity of the air for the season in question, i.e. the

pore moisture content shall be 35-65 %relative humidity. In the case of concreteor light weight concrete elements it maytake a couple of months to attainequilibrium. In situ cast concrete mayrequire much more time.Insulation materials etc. shall be dryWhen blocking up is made of masonryor concrete it must be cured and dry.

A dpc for example a 0.20 mm PE-foilshall be laid before laying the floor inorder to protect the floor againstconstruction moisture.The wooden floor material shall have amoisture content of 8 ± 2 % of which2/3 of the lot should have a moisturecontent between 7 and 9 %.

When wooden floor materials are kilndried to specifications they should not

be unpacked before laying. The moisture content in joists andflooring battens should correspond tothe moisture content in the woodenfloor. The average moisture contentshould not exceed 12 % in the case of

battens and 13 % in the case of joistsand no single value must exceed 14and 15 % respectively.In case the wood is not supplied kilndried, time must be allowed for thewood to obtain equilibrium with themoisture and temperature conditionsexisting in the room.

Wooden materials, glue, caulkingcompounds and similar accessoriesshould be acclimatized for at least 24hours before use. This could be done bystoring such materials inside the roomwhere they will be used.



FLOOR HEATING

Floor heating systems are primarily used inorder to avoid the use of radiators and in

order to achieve a good distribution of heatinside the room. Traditionally, floor heatingsystems have been used in floors withceramic tile covering in bathrooms , butduring recent years an increased used has

been observed in all other rooms of thehouse and also in other floor types , for example in wooden floors.

In new and well insulated houses it is,under normal circumstances, possible toheat a house using a floor heating systemonly. In older houses where the insulationdoes not live up to current requirements it isnormally required to use supplementaryheating sources, for example radiators inorder to meet the heat demand.

It should be noted that wood is a relativelywell-insulating material. As a result woodenfloors, to the touch, feel more comfortable(warmer) than other floor coverings evenwithout floor heating. Thus, from the pointof view of comfort there is no need to usefloor heating in wooden floors in well-insulated houses.

When installing floor heating systemsunder wooden floors the followingconditions shall be observed:

The temperature shall be low in order to

void the drying out of the wood. Thesuppliers normally require that the surfacetemperature does not exceed 25-27°C.The heat distribution below the floor shall

be even not only to ensure maximumcomfort but also to achieve sufficient heatradiation. It is therefore important to layheating pipes or cables in such a way thatno major variances in temperature occur on the surface.

Only such materials and construction principles, including floor heating systems,as recommended by the supplier of the

wooden floor should be used. In this contextthe supplier of the floor is r equired tosupply information concerning the

maximum temperature to which the floor may be exposed and the heating system shall

be constructed in such a way that thistemperature is not exceeded.

In floors where boards or staves can moveindependently it must be expected at leastduring the heating season that the gaps(the joints) between the boards will beslightly larger than normal. This is caused

by the heating of the floor which will causethe drying out of the wood and as aconsequence larger shrinkage across the

boards, see example below. Consideringthis shrinkage it is advisable to usematerials with as little shrinkage as

possible.

One consequence of using floor heating infloors on battens is the heating of the

battens. As a consequence the battens willdry out more than usual. For this reason it is particularly important that the battens aredry when laying the floor as the extradrying out of the battens will causeadditional shrinkage and thereby increasedrisk of squeaking floors see more aboutthis on page 73. It is therefore required toensure that the battens are dried until thyhave the same moisture content as theflooring boards, i.e. a moisture content of 8± 2 %. In order to achieve this it is oftenrequired to stack the joists for a period of 8-14 days inside the room where they will be

used. Notice that prefabricated battens produced from kiln dried wood may alsorequire additional drying in case they have

been stored for a

FLOOR HEATING 3 1

Example:22 x 125 mm pine flooring boards are laid onflooring battens. During the year, the moisturecontent will vary between 6 % during winter

and 13 % during summer. It is anticipated thatthe joints between the boards are totally closedduring the summer. When, in winter, the floor is most dry there will be a gap of (13-6) x 0.22% of 125 mm = 1.9 mm. In case of floor heating the average temperature will increasefrom 21 to 30°C and the moisture contentduring winter will drop to approximately 4 %.Thus the gap will increase to (13 - 4) x 0.22 %of 125 mm = 2.5 mm.



longer period in an unheated warehouse or at the timber merchants.

Floating floors which are glue-jointed inthe T&G will not have the same problemwith larger gaps between the boards duringthe winter. On the other hand, the gap

between the surrounding walls and thefloor may be bigger. In case the floor isloaded with heavy furniture along the wallsthere is an increased risk that the floor maysplit, see more about this on page 74.

Whether the floor heating system is water- borne or electric, it is possible to obtain aneven heat distribution under the floor asshown in figures 37-40.

Before laying the wooden floor it isimportant that all such works that maygenerate moisture, for example masonry work or paintwork, are terminated and the floor heating system must have been working for a

period of at least 14 days. The heating systemis switched off at least 2 days before layingthe floor.

Heating systems used in wooden floorsare purpose made systems, i.e. the systemsare constructed with independent heatingcircuits supplied with an automatic devicecontrolling the floor temperature. If

possible, it is recommended to use a presettemperature control device which does notallow for temperatures above the levelrecommended by the floor manufacturer.

Temperature adjustment should take placegradually as sudden temperature changesmay cause splitting of the wood.

In general, it is not recommended to laywooden floors on top of existing floors withold floor heating systems which are notsupplied with automatic control devices for temperature control.

Floor heating systemsFigures 37-39 show three construction

principles using light constructions where it is possible to control the floor heating with a timeconstant of 1-2 hours, i.e. it is possible to adjustthe room temperature fast, for example whenthe room is subject to insolation (sun throughwindows) or when there is a need to reduce thetemperature during night.

Heating pipes between battens or between joistsWhen heating pipes are placed between

battens or joists it is common practice toclip the pipes into so-called heatdistributing panels placed in close contactwith the underside of the floor in order toobtain a good temperature distribution.

The heat distributing panels are producedwith a groove into which the pipe fits, seefigure 37. It is required to use pipes with adiameter corresponding to the size of thegroove in order to ensure good contact

between pipe and panel. The pipes shouldnot touch the underside of the floor.

It is common practice to use anintermediate layer such as flooringcardboard or felt in order to reduceclattering and squeaking, see figure 37.

Heating pipes on top of battens or joistsWhen the heating pipes are placed on top of the joists or battens it is required to place anadditional layer of boars or battens

perpendicular to the direction of the joists or battens. This layer serves as underlay for theheat distributing panels. Otherwise theconstruction is carried out as describedabove, see figure 38.

Boards are used in cases where chipboardis used as a structural floor serving asunderlay for a floating wooden floor. Thedimension of the chipboard is defined inaccordance with the distance between the

joists of flooring battens as the additionallayer of boards is not considered to be loadcarrying.

Battens/planks are used as underlay for the heat distributing panels in cases where

the flooring boards are laid parallel to joistsor flooring battens. In this case theadditional layer is load carrying and the

battens/planks shall be dimensioned inaccordance with table 5, where the blockingup distance will be equal to the distance

between the flooring battens/joists. The blocking up distance my be reduced byinserting additional flooring battens or

joists.

32 FLOOR HEATING



Heating pipes on heat distributing panels

InsulationJoistsBoards (25x100 mm) on

battens c/c 600 mm

Figure 37 Heating pipes placed on heatdistributing panels which again are placed on t op

boar ds placed on stru ctura l j oist s or floorin g batt ens . The heating pipes cross the joists in thezone outside the end of the joist in order not toweaken the joist by cutting into it. Flooring boards

are screwed or nailed.

Figure 38 Heating pipes on heating distributing panel s placed on s tru ctura l joi sts. Here shown wi th

chipboard as structural floor and floating woodenfloor. May also be carried out with structural battens ( replaci ng ad ditional boar ds) and floor boards.

Heating pipes in floor heating slabs.Floor heating slabs consist of one layer of insulation material (usually polystyrene)and heat distributing metal sheets. The floor heating slabs are supplied with ready madegrooves fitting the heating pipes. The slabsare placed on top of a structural underlay andthe pipes are placed in the gooves. Anintermediate layer (flooring cardboard or felt)is placed between the slabs and a pressuredistributing subfloor made of chipboard ontop of which a floating floor may be laid, seefigure 39.

Wooden floor possibly on top of pres sure distr ibuting sub floor

Figure 39 Heating pipes in »Floor heating slab«,i.e. insulating slabs made of polystyrene suppliedwith heat distributing metal panels. An intermediatelayer of flooring cardboard or felt is placed betweenthe heating slab and the floor above in order toreduce impact sound. The floor is laid as a floatingfloor.

FLOOR HEATING 33

Chipboard as structural floor Intermediate layer

Heating pipes on heatdistributing panels

Floating wooden floor

Intermediate layer

Damp proof courseThe purpose of placing a dpc in wooden floorswith floor heating is to secure the wood against tundesired moistening. The placing depends onthe construction in question and also depends onwhere in the building the floor is placed. It isrecommended to consult with SBI-Direction 178or to ask advice from the floor supplier.

Insulation

Intermediate layer

dpc

Concrete slab

Intermediate layer

Floor boards or parquet boards

Addtional boards carrying heatingpipes

Heating pipes on floor heatingslab



Embedded heating pipes and cablesWhen embedding heating pipes or cables inconcrete there should be a cover layer of minimum 30-70 mm on top of the pipes or the cables in order to achieve an even heatdistribution and the wooden floor should be

placed as close as possible to the underlay,see figure 40. An efficient dpc, for example

bitumen felt, should be placed between theconcrete and the wooden floor in order to

prevent the transportation of moisture(released from the concrete by the heating)from concrete to wood.

It is difficult to adjust the heat radiationrapidly because of the heat accumulatingcapacity of the concrete which causes thetime constant for this type of floor to be ashigh as 12 hours.Heavy constructions used to be considered anadvantage as they were able to accumulateenergy during periods with sun and releasethe energy again during the night With the thickness of insulation appliedtoday this capacity is no longer interesting. .

Figure 40 The embedding of heating pipes inconcrete gives an even heat distribution. The

placing of dpc and insulation depends on theconstruction in question consult experts in thefield.

Maximum effect for floor heating systemsThe effect should never exceed 100 W/m 2

Figure 41 Electric cables in levelling compoundshould be so placed that they are covered withminimum 10 mm levelling compound to ensureeven heat distribution.

Electric heating mats/electric cables placed in levelling compound.Electric-based heating systems may also befitted using levelling compounds. The totalheight of this construction is very low. Thecables may be placed directly on top of aninorganic underlay or placed on a wooden

based underlay with minimum 5 mmlevelling compound between the cable andunderlay. In order to ensure an even heatdistribution the thickness of the levellingcompound on top of the cables should be atleast 10 mm, see figure 41. It isrecommended to use a fibre reinforcedlevelling compound which is capable of resisting foreseen temperatures. .

One significant difference between electricsystems and water borne systems is the factthat the electric system gives a fixed effectand as a result high temperatures may occur under thick carpets, furniture etc. In order toavoid excessive heating it is recommendedonly to use such cables and mats which arecapable of supplying the heating requiredwith the lowest effect possible and never exceeding 100W/m 2. A low effect providesthe same comfort as a high effect, but will of course result in a slower regulation of thetemperature. In practice, this is not a problemas the temperature is normally set to a certainsurface or room temperature once and for all.

34 FLOOR HEATING

Wooden floor

GlueLevelling compound, minimum 10 mm

Levelling compound.Electric-cables

Wooden floor

Intermediate layer

Possibly dpc

Concrete slab with 30-70 mm cover layer

Reinforcement meshPossibly insulation

Concrete slab



Aspects related to energyIt is imperative to follow carefully theinstructions issued by the floor manufacturer when laying and using wooden floors withfloor heating including recommendationsconcerning the types of floor heating andconstructions which may be used and whattemperatures the floor may be exposed to.

Under furniture and floor coverings, for example under book cases and carpets with agood heat insulating capacity the floor temperature may be higher than thetemperature in reamining floor. This maycause extra large joints between the floor

boards during winter.The limited surface temperature

obtainable also determines the effect whichmay be released by a floor heating system.As a guideline it may be reckoned that afloor heating system may release an effect asexpressed in the following formula:

Released effect = 10 x (t f - t r ) W/m2 ,

where t f is the surface temperature of thefloor and t r is the room temperature.

When calculating with this formula usingthe most commonly occurring surfacetemperatures we get the results shown intable 3.Table 3 Released effect in wooden floors withcommonly occurring surface temperatures and witha room temperature of 21°C.In comparison the energy need for new single familyhouses insulated in accordance with BR-S 98:45 W/m 2

Maximum surface temperatureThe surface temperature in the woodenfloor must not exceed 25-27°C.Depending on thickness this correspondsto the following temperatures on theunderside of the wooden floor:

22 mm thickness: 33-34°C14 mm thickness: 30-32°C10 mm thickness: 28-30°C

The temperature difference betweenupper- and the underside depends on floor thickness, wood specie and materialcomposition (solid/laminated).

Surface temperature °C Effect W/m225 °C 40

26°C 5027°C 60

Best in well insulated housesThe heating with floor heating is onlysufficient in new and well insulated houses.When remodelling houses it is recommendedto use supplementary heat supply in additionto floor heating, for example in the form of

FLOOR HEATING 35

When placing floor heatingunder wooden floors –remember:

Floor heating may only be usedtogether with such products suitable for the purpose and approved by thesupplier.The floor heating system shall ensure aneven heat distribution on the floor surface. The floor heating system shall besupplied with a preset temperaturecontrol device which does not allow for temperatures above the levelrecommended by the floor manufacturer.Only such floor heating systems asrecommended by the floor manufacturer may be used.The need for supplementary heating fromradiators is likely in older houses.Flooring battens/joists shal be dry in order to avoid squeaking.Avoid the laying of wooden floors ontop of old floors with floor heatingwithout automatic temperature control.Furring boards placed as underlay for heat distributing panels are countersunk

between joists or flooring battensIn electric-based flooring systems theeffect must not exceed 100 W/m 2.In water-borne heating systems the pipesmust not touch the flooring boards.



radiators. This is due to the fact that theinsulation in older houses is normallyinferior to present requirements and as aconsequence the effect needed is higher.

Larger energy consumption

In general larger energy consumption may be expected when using floor heatingcompared to the use radiators. This is thereason why the building regulations BRS 98require additional insulation in groundsupported floors and in storey partitionsfacing the outside or facing ventilated crawlspaces when such floors are supplied withfloor heating. In these constructions themaximum U-values are: s

In multi-storey buildings:0.12 in stead of 0.15In single family housesand the like.:0,.12 in stead of 0.15

Also floors above heated rooms should besupplied with insulation under floor heatingsystems in order to prevent the undesiredheating of the room below and in order tosave energy.

W ET ROOMS

Because of its beautiful texture it has become very tempting to use wood as

flooring material in wet rooms. However, itis against regulations to substitutetraditional ceramic tiles or PVC floors withwooden floors, cf. B&B-Direction 200Wet rooms . There reasons are several:Generally speaking, wood is not suited to

withstand constant exposure to water or excessive humidity as such exposure maycause the growth of fungi and worst casescenario rot or dry rot. The combinationof elevated humidity and high temperature common to bathrooms is very productiveto the growth of dry rot.

Wooden flooring boards are narrow and as

a consequence there are many joints. Add tothis that most floor are laid as so-called strip plank decks with caulked joints (elasticcaulking compound).

As a rule of thumb, the water tightness inwet rooms must not be based on the use of elastic joints because such joints are not longterm watertight.

Even in cases where a watertightmembrane has been used there is a risk thatwater may penetrate the joints which maycause the growth of fungi and or bad odour.

Seen in this light, wooden floors in wetrooms are only accepted in the followingcases:

When fixed on top of a finished, approvedand consequently watertight floor, i.e.inclusive floor covering of ceramic tilesor PVC.In areas of the room not frequentlyexposed to water.On the condition that the wooden floor may be removed again without damagingwet room constructions.

In general it is not recommended to usewooden floors in wet rooms because of the

increased risk of obnoxious smells, growthof fungi and possibly rot or dry rot in caseof excessive humidity.

36 WET ROOMS



Under all circumstances it must beconsidered that wooden floors will have ashorter lifetime compared to other surfacesused in a bathroom and as a result they must

be substituted more frequently.It is an obligation to inform the client that

the risks of inconveniences related to the useof wooden floors as supplementary floor covering is entirely his own responsibility.Should the client still want to use woodenfloors, such floors must only be laid in lessexposed areas of the wet room, and, in order to minimize the risk of inconveniences,observing the guidelines indicated in thesummary on page 38, figure 42.

The wooden covering shall be kept wellaway from areas particularly exposed tomoisture, for example shower stalls, bathtubs and floor drains, se figure 41. No pipe

penetrations are accepted in the wooden floor and it is not accepted to establish a floor drain, see figure 43 and the guidelines on

page 38.The wooden floor must be treated and

maintained in accordance withmanufacturer s instructions. As the use of wooden floors in wet rooms increase therisk of bad odours, fungi attack etc., it isrecommended:

To immediately remove free water fromthe floor surfaceTo pay special attention to any signs of or symptoms, which may indicate water

penetration, moisture or the presence of

fungi.

Figure 43 It is not accepted to construct woodenfloors in wet rooms with floor drains or pipe

penetrations.

Figure 42 Wooden floors are onlyaccepted in wet rooms provided they layon top of an approved watertight wet roomfloor and observing a distancerequireement of minimum 500 mm awayfrom shower stalls, bath tub and floor drain.

V ADRUM 37

Wooden floors in wet roomsAre beautiful- but only serve as decorationCannot substitute ceramic tiles or PVC

flooring as watertight underlay.May cause risk of fungi attack etc.See guidelines for the use of wooden floors

in wet rooms on page 38.



A SPECTS RELATED

TO SOUND

Floors on battensIn case there is a demand to the reduction of impact sound on wooden floors it isrequired to place a piece of soft material, for example a porous wooden fibre with athickness of maximum 13 mm and glued toa pressure distributing piece of plywoodsee page 12. The thickness of the softmaterial shall be equal in all blocks used for

blocking up.The packing pieces shall be fixed to the

battens using toe-nailing, i.e. a nail enteringthe batten on the side and continuing at anangle into the block or wedge, see figure 58.The nail must not enter the soft material.

An alternative packing method to wooden blocks (combined with soft blocks) is the useof plastic wedges. When using wedges madeof hard type plastic, the impact sound levelmay be increased by 0-4 dB. Always contactthe wedge manufacturer for further information concerning impact soundreduction.

Battens and floor boards shall be kept at adistance of minimum 10 mm away fromsurrounding walls and pipes penetrating thefloor.

When electric cables and heating pipesrun under the floor it is required to keep adistance of 10 mm between cable / pipe and

batten. Notches made for pipes or cablesshall also observe the 10 mm rule.

In case a floor continues under thethreshold, it is recommended to establish a20 mm joint between floor boards and

between joists under the threshold, seefigure 44.

The use of chipboard or plywooddrastically increases the stiffness of thefloor as compared to floor boards. As a resultthe sound diffusion from the floor plane will

be increased and the impact sound insurrounding rooms will increase as will also

the drum sound effect in the room inquestion. It is difficult to reduce the drumsound effect in rooms with wooden floors.Some reduction may be achieved byinserting mineral wool or sand in the cavity

between the battens/joists.

38 ASPECTS RELATED TO SOUND

Guidelines for the use of woodenfloors in wet rooms

The wet room shall have an approvedand completed floor, i.e. inclusive afloor covering made of PVC or ceramictiles.Wooden floors are only allowed inimpact class L (low) with few baths per day and of short duration and efficientventilation after use. Low impact class is

particularly found in single familyhoses, summer houses and the like, cf.B&B-Direction 200 Wet roomsThe wooden floor must have a plainunderside with as few cavities as

possible along T&G joints and the boards should not be supplied with stressgrooves on the underside.The wooden floor is full-face glued to

the underlay in such a way that cavities,which may contain water, are eliminated.In order to prevent the penetration of water, all joints between boards andalong adjoining walls are caulked with amastic caulking compound.The joints must be inspected at regular intervals and repaired in case leaks aredetected.Wooden floor and materials used -including adhesives, caulkingcompounds and underlay must becompatible.A distance of minimum 500 mm

between the floor and shower stall, bath

tub and floor drain must be observed,see figure 42. No pipe penetrations or floor drains areaccepted in the wooden floor (neither isit possible as no flor drains have beenapproved for the use in wooden floors)see figure 43.Accepted species are teak and specieswith similar characteristics in terms of resistance and durability when exposedto moisture.Good heating and efficient ventilation isrequired in order to keep the room asdry as possible and thereby prevent theattack of fungi.



Floating floorsFloating floors with an elastic intermediatelayer in the form of an insulation materialwill reduce the impact sound level.The thickness and the elasticity(compressibility) of the layer greatlyinfluence the potential impact soundreduction. Large thickness and largecompressibility give high impact soundreduction.

The use of thin insulation below 10mm requires a completely levelsubstrate. Roughness in the underlaycaused for example by a pointed concretesurface may be pressed into the insulatinglayer and may cause contact between thefloor and the underlay, hereby increasingthe risk of sound bridges, see figure 45. Thefloors must not touch the surrounding wallsor pipes penetrating the floor.

The efficient sound reduction in floatingfloors very much depends on correctconstrution. For further informationconcerning sound insulation reference ismade SBI-direction 172, Sound insulationin buildings - newer buildings and to SBI-direction 173, Sound insulation in buildings- older buildings.

Figure 44 Construction details ensuring impactsound reduction in floors on battens.

The latter also discusses possibilities of improving sound insulation in old storey

partitions by adding supplementary floor coverings on top of existing.

Figure 45 Construction details impact soundreduction in floating floors.

ASPECTS RELATED TO SOUND 39

Minimum 20 mmMinimum10 mm fromwall

LInsulated jointunder threshold

Minimum. 10mm above pipesSoft blocks

InsulationBatten

Minimum 10 mmclearance aroundpipes

Minimum 10 mmclearance

Minimum 10 mmfrom wall

Intermediate layer reducing impact sound

Wooden floor

Sub floor

Risk of sound bridges caused by pointed concrete



J OINTS

The purpose of establishing joints inwooden floors is: 1) to absorb expansions,

2) to transfer forces and 3) to establish acharacteristic subdivision of the floor surface.

Differentiation is made between dilatation joints and insulation joints see figure 46.The purpose of d ilatation joints is to absorbmoisture and temperature causedmovements between materials in the floor

plane, figures 48-49. Dilatation joints arenormally only found in floating floors.Suspended floors on battens or on joists aswell as glued or nailed floors do notnormally require dilatation joints, providedthey are constructed correctly.

Insulation joints are used to separatefloors from adjacent building componentssuch as columns and walls, see figure 50.Insulation joints may function as dilatation

joints at the same time.Joints shall be so designed that they are

capable of absorbing such movements asmay be expected in the floor plane inquestion. The number and position of jointsare determined by type of floor construction, load, and expected moisturevariations as well as geometry of the roomand the wood species used.

In case dilatation joints have been

established in the sub floor, such joints must be repeated in the wooden floor.Mastic caulking compounds and soft

synthetic rubber profiles are used for smaller joints. Metal profiles are primarilyused when excessive movements areexpected in the floor plane.

Floating floorsLarge mechanic loads, for example from

book cases or reception desks in open spaceoffices may impede the movements of floating floors, see figure 46. This fact mayreduce the size of floor areas constructedwithout joints. The use of hard and strong

joints against adjacent floors or buildingcomponents may hamper the free movementof the floor plane.

Figure 46 The placing of dilatation and i nsulation joint s in floa ting floors.

Areas where large movements may beexpected, as a consequence of moisturevariations, require several wide joints of high quality. Movements must not behampered in floors with irregular geometryand with columns penetrating the floor, seefigure 46.

Subdivision of the floor plane should, as

far as possible, be carried out in rectangular fields in order to allow for equal size of expected movements in both directions.Under normal circumstances it is possible toconstruct floor planes without joints up to8x12 m, where 12 m is the longitudinaldirection of floor boards. When constructinglarger floors it is advisable to consult thefloor manufacturer.

End grain wood block floorsExpected moisture related movements inend grain wood block floors is greater thanin most other wood floors. Reference is

made to the guidelines issued by the floor manufacturer concerning field sizes. Suchguidelines should be observed.

40 JOINTS

Dilatation joint

Dilatation joint

Dilatation joint Insulation jointaround column

Dilatation jointbetween columns

Dilatation joint

Insulation jointaround heavy fixedfurniture

Dilatation joint



Joints and caulking compoundsElastic polysulphide-, MS-polymers - or

polyurethane compound are used inwooden floors. With respect tocompressibility and wear the compounds

must have a hardness corresponding to40-65° Shore A. In joints along wall a moreflexible compound is used. In order toavoid the adherence to the bottom of the

joint it is required to use slip tape, seefigure 47. Caulking compounds indilatation - and insulation joints mustalways be supported from below, seefigures 48-50. Therefore never caulk

joints without backing.The width of the joint should be minimum

8 mm and maximum 15mm. Along wall,columns etc. the joints may have a width upto 30 mm.

In as far as it is possible the cross sectionof the joint should be square. When usingthick floor boards this may requireadjustment of the joint depth for example bythe insertion of pressure resistant, acid freecardboard EPDM profiles or polyester needle felt, see figures 47 and 50.

Documentation showing compatibility between applied caulking compound andwood species must be available. This is

particularly important when using speciescontaining oil, for example teak. In suchcases the supplier s instructions concerning

priming must be followed carefully because

the extraction of oil and resin from thewood may cause the forming of blisters inthe caulk.

Figure 48-50 Dilatation and insulation jointsshall always have support from below, for example by the use of a metal bar serving as aloose tongue between to floor planes (49) or aloose batten under floors on battens (48 and 50).

Documentation must also be madeavailable on the compatibility between oil,varnish and other remedies for surfacetreatment.

Joints must be carried out inconsultation with the supplier of thecaulking compound in order to ensurecorrect choice of compound and primer.IAs a rule of thumb all adhering surfacesmust be cleaned and primed according tosupplier s directions. The caulk groovemust have clear cut and sharp edges. .Wooden surfaces bordering the joint must becovered with tape before caulking.

Floor which requires sanding may besanded with course sandpaper beforecaulking. Fine sanding takes place when thecaulking is hardened and after removal of excessive compound (by cutting).

For further information, reference is madeto guidelines issued by FSO.

JOINTS 41

Possible adjustmentof joint depth

Caulking compound

Caulking compound Caulking compound-Slip tape-

Loose metal tongue -Joint support

for example aloose batten

Floor batten

Adjustment of joint depth

Figure 47 Placing of bottom stop, for exampleslip tape. The joint depth should be adjusted inorder to establish a square caulk profile.

Caulkingcompound

Caulkingcompound

Slip tape

Adjustment of jointdepth



Movement profilesJoints designed with metal profiles or extruded rubber profiles are used in areaswhere large movements are expected or where adherence between the materials onthe two sides of the joints is not accepted

see figure 52.A movement profile can be made withmetal anchoring legs (for examplealuminium) connected to a movement zonemade of soft synthetic rubber as shown infigure 52. Such profiles are available for wood / wood joints and for wood joiningother flooring materials. Special designsalso exist for the joining of floors withdifferent height levels. The profiles are

produced in a number of special designs,for example with angles for corners and inT-shape. The EPDM rubber profiles are

produced in a number of different designs,for example angle corners or T-shapes. Therubber is normally renewable.

Figure 51 Open joints covered with metal profile(cover strip). Is applicable to all floor types, seemore details in section Laying guidelines (page58)

Movement profile withvisible anchoring legs

Always use metal profiles or extrudedrubber profiles where the freemovement of the floor is desirable

Movement profile withconcealed anchoring legs

Ships plank joint / groove for filletShips planks are made by routing a groovenext to the tongue on the top side of the

boards. The groove is filled with a contrastmaterial in order resemble the originalcaulking. This contrast material can be acaulking compound, a wooden fillet, or a

rubber fillet, see figure 53. Ships plank joints can also be established by theinsertion of loose fillets between the boardssee figure 49.

When ships plank joints are made using acaulking compound it is important to noticethat the cross section should be squaresimilar to other joint between flooring

boards. Bottom stop and priming is alsoimportant. Course sanding of the floor takes place before caulking, and finesanding only takes place after proper hardening of the caulking compound.

When ships plank joints are made using

wood or rubber fillets, the fillets are placedin the routed groove where they aremechanically fixed and / or glued in aspecially created key. Wood fillets areglued with water resistant PVA-glue.Rubber fillets should be glued with glues asspecified by the supplier. Rubber filletsmay be joined at ends using cyanoacrylateglue (10-seconds glue).

Figur 52 Top: Visible stanard profile fixed fromabove. Best solution for dilatation joint in glued /screwed floors.

Bottom:: Concealed standard profile anchored tothe sub floor before laying the wooden floor. The profi le is countersunk into the subfloor in order toestablish a plane surface.

42 JOINTS

Metal cover strip Metal cover strip

Figure 53Examples of grooves using caulkingand loose fillet



LAYINGINSTRUCTIONS

The choice of underlay for wooden floorsshall be adjusted to the type of floor inquestion and shall always be sufficientlyrigid and plane in order to ensure the correctlaying of the wooden floor.

CoveringUnder normal circumstances a woodenfloor should always be covered immediatelyafter laying in order to protect the floor against damages during the remainingconstruction period. Materials used for covering could be cardboard or woodenfibre boards.

Walking lines, door steps and staicases,which are particularly vulnerable, shouldalways be covered with cardboard or hardwood fibre boards. The wood fibre boardsare fixed by taping to the underlayingcardboard using an appropriate tape inorder to avoid the undesired entering of dust and dirt particles under the covering,where such particles may cause dents andscratches in the finished floor. On door steps and staicases the fibre boards may befixed using small pins along edges.

Wooden floors on battens or joistsFloors on battens are normally laid on asubstrate of concrete or light weight concrete,

but may also be constructed on top of awooden sub floor. When laid on concrete it isrecommended always to lay a dpc beforelaying the floor in order to avoid problemsoriginating from the presence of constructionmoisture or from capillary rise of groundmoisture. The dpc could for example be aminimum 0.20 mm PE-foil laid withminimum 200 mm overlap at joints.

Distances between supportsThe support distances for suspended floorson battens are indicated in tables 4 and 5.The distances indicated ensure a reasonablystiff floor preventing inconvenientvibrations when walking and preventing theinconvenient inclination of furniture andequipment caused by floor deflection. Thesupport distance depends on the chosenthickness of materials and the expectedload, see figure 54.

Figure 54 Batten or joist distances as well as blocking-up distances are measured form centre tocentre (c/c)

The laying of battensAs a minimum requirement, the battensshould be planed and straightened on oneside and be in one piece.

The first row of battens is placed 50-80mm away from the wall. Along walls, whereheavy loads normally occur, extra battens are

placed as shown in figure 55 (unlessotherwise instructed by the manufacturer).The battens are placed with the desireddistance and chocked with blocks, wedges or similar in order to adjust the height,establishing a plane surface across the

battens. Blocks or wedges must rest on a plane surface in order to secure stability.

Figure 55 The placing of battens. Notice the extra

batten along walls and the staggered packing of battens.

FLOORS ON BATTENS 43

Extra batten approx. 70 cm

Block

Extra batten



* Guiding values

Wooden based blocks used as packing pieces should always be glued together inorder to avoid displacement. The packing

piece material should be fixed to the battenwith a nail in order to avoid displacementduring the laying and later during the use of the floor. The fixing also helps preventingsqueaking floors. The usual nailing methodis toe-nailing , i.e. a nail entering the

batten on the side and continuing at anangle into the block or wedge, see figure 56.

When soft blocks are used with the purpose of sound reduction, care must betaken to ensure that the nail does not enter the soft material, see figure 57. The densityof the soft wood fibre board shall be 225-300 kg/m 3 and the size shall be minimum

100 cm2

, for example 100 x 100 mm, in order to avoid settlement in the floor when loadsare applied. The plywood block placed ontop must have the same dimension, seefigure 57.

In basement floors and on groundsupported floors extra care must be taken inorder to avoid the absorption of moisture. Itis therefore recommended to place a piece of

bitumen felt (200 x 200 mm) below the packing pieces.

Figure 56 The packing of battens using wedges

44 FLOORS ON BATTENS

Floor material Batten or joist distance

Minimum thickness in mm Dwellings etc. Smaller shops Assembly rooms or the like

Flo or board s20 mm tongued and grooved boards 520 420 360

22 mm tongued and grooved boards 600 490 42025 mm tongued and grooved boards 720 590 50028 mm tongued and grooved boards 860 700 60030 mm tongued and grooved boards 950 770 670Structural sub floors*15 mm Plywood glued in T&G 400 350 32018 mm Plywood glued in T&G 600 520 48022 mm Flooring chip board glued in T&G 600 520 480

Toe-nail

Wedges

Packing100x100 mm

Possibly bitumenfelt 200x200 mm

Table 4 Batten and structural joist distances calculated from centre to centre The distances ensureagainst undesired deflection and vibrations. When a calculation indicates a dimension somewhere inbetween the indicated distances, the nearest lower distance should be applied.

Wooden floor

Batten

Batten

Figure 57 Chocking-up battens using wooden blocksand posiibly bitumen felt. When soft blocks are usedwith the purpose of sound reduction, care must betaken to ensure that the nail does not enter the softmaterial

Soft block,100x100 mm

Wooden floor



Floor on battens

Figure 59 Packing of battens by the use of high plastic wedg es create s su fficien t s pace for therunning of pipes.

Figure 58 When packing battens on a woodenstorey partition the position of the packing piecesmust be aligned and in line with structural joists

below a nd c omply with distanc es indicat ed i n t able4. When battens are positioned perpendicularly tostructural joists, it is required to choose a battendimension which allows for a chocking-updistance at least coresponding to the distance

betw een the stru ctura l joist s.

Chocking-up on top of structural joists isshown in figure 58. The overall height of the packing pieces must allow for a gap of minium 10 mm between batten andunderlay. In case pipes or other installationsare placed under the floor, there must be atleast 10 mm between such installations andthe batten.

Pipes under the floor shall be well-insulated in order to avoid the undesiredheating of the wooden floor, see figure 59.

In case incisions are made in the battens,it is required to establish an additionalsupport on either side of the incision, seefigure 60.

Battens shall always be supported at butt joints (end joints), see figure 61. Butt jointsmust not be aligned under the same floor

board.

Figure 60 When incisions are made in the bat ten s, for exa mple for pipes ,it is req uir ed toestablish additional supports on either side of the incision.


Toe-nail Toe-nailPacking Insulated pipeSoft block

Plastic wedges

Possibly dpcWooden joist/woodenstringer

Wooden deck element or wooden storey partition

Batten Insulated pipe

Incision

Soft block

Minimum10 mmdistanceto batten

Wooden floor Batten



In renovation work, where it may beimpossible to avoid the aligning of butt

joints, it is required to reinforce the jointswith fishplates on either side of the joint,using for example 12 mm plywoodfishplates minimum 300 mm long. Thequality of the plywood used must, as aminimum, correspond to American C-D or

better.When joints asr e made without the use of

fishplates it is required to support each endof adjoining battens using packing pieceswith a minimum length of 125 mm(measured along battens). The packing

pieces are placed roughly 50 mm from theends of the battens see, figure 61.

The distance between packed basesdepends on batten dimension, as shown intable 5. The spacing between packed basesshall be reduced at batten ends and batten

joints, see figure 62.When, in exceptional cases, stress relief

cuts are established, it is required to place packed bases under each such cut and thespacing between bases shall be reducedaccording to figure 62.

Spacing of packed bases andBattens used as underlay for wooden floorsshall be sufficiently stiff in order to ensurethat it feels safe to walk on the floor.

Table 5 shows the normal spacing between packed bases (l max in mm) for anumber of cross sectional dimensions andtypes of battens

The spacing shall be reduced by at least10 % along batten ends. This also applies to

battens butt joints and possible stress relief cuts, see figure 62.

In dwellings, offices and light industrythe point load Q is set to 2 kN, for smaller shops Q equals 3 kN, and for assemblyrooms and bigger shops Q is set to 4kN.

The spacing between supports and packed bases indicated in tables 4 and 5may be used in normal rooms according tomentioned user classes. In cases where thefloor is temporarily exposed to loadsexceeding the loads normally occurring inthe user class in question, it is required toreduce the distance between supports and

packed bases in accordance with theexpected extra load, for example fromelectric wheelchairs, trucks and heavy

book cases.

The spacing between packed basesis reduced by minimum 10 % at

batten ends.

Figure 62 The distance between packed bases shall be reduced at batten ends, at batten joints and wherestress relief grooves are established. The reductionnormally corresponds to 10 % of normal spacing.


Fishplates minimum300 mm

Maximum 100 mm

Figure 61 An additional support shall always beestablished when battens are butt jointed or

joined with fishplates.

Spacing betweenpacked bases

÷ 10 %



Table 5 Spacing of pa cking pieces and cradle systems under floor battens in main floor area. Along ends of bat ten s t he spa cin g sha ll be re du ced by 1 0 %, see fig ur e 62 . De sig n a ssu mpt io ns f or ta ble 5 ar e de scr ibe d on pag e 48.

Batten Dwellings, offices anddimension light industriesheight x width (Q = 2 kN)mm Sawn Laminated

batt ens 1 battens 2

Smaller shops

(Q = 3 kN)Sawn Laminated

bat ten s 1 battens 2

Assembly rooms andlarger shops(Q = 4 kN) ____________ Sawn Laminated

bat ten s 1 battens 2

1 The indicated distance is allowed provided the wood used has a stiffness corresponding to K18 (E0 = 9000MPa)

2 The indicated distance is allowed provided the laminated wood used corresponds to L30 (E0 = 12000 MPa)or to L40 (E0 = 14000 MPa). The stiffness in laminated products depends on number of layers, wood qualityand production method. Supplier will inform about Elasticity module upon request.

3 Sawn battens produced from solid coniferous wood and graded in accordance with grading class T1 willcomply with strength class K18 requirements.

4 Laminated battens produced (glued together) from planed coniferous staves will normally achievestrength/stiffness properties equivalent to strength class L30.

5 Laminated battens type LVL (Kerto and others) normally have) v strength/stiffness properties equivalent tostrength class L40.




The laying of floor boards nailed or screwed.Before laying the floor it is required to pack of batten supports in order to establish alevel surface across the battens. This iscontrolled by the use of a straightedge and aspirit level or by laser levelling, see figure63. The first row of boards is laid with thegroove facing the wall. The boards arealigned using a building line. A clearance of

minimum 10 mm between wall and floor board must be observed. In larger rooms it isnecessary to increase the distance, dependingon room dimensions and floor product inaccordance with manufacturer s instructions.

Temporary distance blocks are placed between the first row of boards and the wallin order to avoid the displacement of the

board during laying. see figure 63.


Design assumptions used in the calculation of spacing between packed basesand other supports under floor battens:

Maximum support distance l max for supportsunder central part o a batten with thewidth b , the height h and the effective E-module Es and exposed to point load Q can

be determined by the use of this formula:l ma x

3= l0mm bh 3Es/Q

The distance is rounded off to whole 10mm units. Along ends, and in rare cases of stress relief cuts in battens, it is required toreduce the support distance by 10 %.

The constant 10 mm has been chosen insuch a way that lmax becomes 600 mmfor a sawn batten with cross sectionaldimensions of 45x45 mm and normalstiffness Eo = 9000 MPa (Structuraltimber class K18).

Table 5 shows the support distances for a

number of cross sectional dimensions andcode stiffness with maximum supportdistance l max in central floor area as afunction of point load, wood quality and

batten dimension. In dwellings, officesand light industry the point load Q = 2kN,in smaller shops Q = 3 kN and in assemblyrooms and larger shops Q = 4 kN.

It should be noticed that battens are not part of the load bearing structure and assuch are not subject to code requirements.Consequently, it is irrelevant whether calculations show whether or not the

battens will be able to accept assumed

point loads in DS 410:1998.

Battens used as underlay for wooden floorsshall be sufficiently stiff in order to ensurethat it feels safe to walk on the floor.The below mentioned formulas describe the

acceptable distances between batten supportsdepending on load, cross sectionaldimensions and wood quality (E-module).The formulas are defined on the basis of traditional norms, but adjusted to loads andstiffness requirements listed in DS 410:1998Code of Practice for Loads for the Design of Structures and in DS 413:1998. Code of

Practice for the structural use of timber The code values for point loads and surface

loads in different user classes (for exampledwellings, offices, assembly rooms) areassumed to represent the correct mutualrelationship between loads. In practice, the

only factor of real interest is the deflectioncaused by the point load.The stiffness of normal structural timber is

usually much higher than the mean value Eo stated in DS 413. In order to achieveuniform stiffness in battens made of traditional structural timber and in battensmade of processed materials with a

predefined stiffness, the effective E-moduleused in following will be defined as:

Es = 12000 Eo MPa for Eo < 12000 MpaEs = Eo for Eo 12000 MPa



Figure 63 The battens must be completely level and stable. The boards are aligned using a building lineand clearance is established along walls.

Floor boards nail ed / screwed fr om above.When boards are fixed using visiblenailing /screwing, the nail / screw is placedat a distance corresponding to ¼ of the

board width from the grooved edge of the board. When boards are particularly wide,i.e. more than 200 mm, the visible nailing/screwing requires two nails / screws inevery board, see figure 64.

In the case of secret fixing from above,the boards are fixed using countersunk wood screws. Screw holes are pluggedwith wooden plugs, see page 19. Otherwisethe floor is laid in accordance withguidelines applying to floors with hiddennailing / screwing.

Figure 64 Floor boards - screwed / nailed from above.In case the boards are wider than 200 mm it is requiredto use two screws / nails according to distancesindicated.

FLOORS ON BATTENS49

Distance blocks

Tongue

Groove

Tongue Groove

Straightedge

Batten

Extra batten

Extra batten Dpm - optional

Min. 50 mm

Distance blocks,minimum 10 mm

Batten



Floor boards with hidden nailing Floor boards may be fixed using hiddennailing or hidden screwing. When boardsare screwed, pre-drilling is always required.

The first board is nailed to the batten fromabove and by the use of hidden nailing inthe tongue, see figure 65. The visible nail inthe first board is places roughly 20 mm fromthe grooved side of the board. Finishingnails are driven into the wood with a nailset, and the holes are filled with adequatefiller.

The tongue side is fixed by hidden nailingfrom the upper side of the tongue the nailsare placed at an angle roughly 45-60° inrelation to the upper side of the floor board.

Nails are driven into the wood. It may benecessary to pre-drill in order to avoiddamaging the tongue, see figure 66.er

It is recommended to blunt the nail point inorder to avoid splitting of the wood. Whendoing so, the head of the nail may be usedto drive the previous. Doing so, the nailhead becomes slightly rectangular. Placingthe long side of the nail head parallel to the

board will reduce the risk of splitting.Guiding dimensions for nails are

indicated in table 2, page 17. Boards arenailed in all battens. However, it is notrecommended to nail at a distance shorter than 50 mm from the end of a board, seefigure 64.

Subsequent boards are laid and knockedtogether using a hammering block or ahammering rail making sure to observe the10-board measurement, see figure 67. Thehammering block, in some cases, be madefrom a board off-cut. In other sases it isrequired to use a special hammering block in order to avoid damaging the profile.

Figure 65 Fixing the first board and nailing principles in remaining boards.

Figure67 The boards are knocked together usinga hammering block or a hammering rail.

Figure 66 Placing and dimensions of nailswhen nailing through the tongue (hiddennailing).

Cupped and warped boards can be difficultto force in place alone by nailing. The useof wedges as shown on figure 68 may helpsolving this problem forcing the board into

place. Clean cut board ends must be joinedalong batten centreline. Butt jointed boardsshould have the same orientation of annular rings in order to avoid the curving in

opposite directions when the boards dry out,see figure 69. Boards are square cut in order to ensure a tight joint. In order to further secure a tight joint both cuts may haveslight inclination away from the joint, seefigure 69.


Hammering block

2.8x65 mm3.1x80 mm3.4x90 mm3.4x90 mm

Floor board Batten

Packing pieces



Figure 68 Warped boards may be forced in place by t he us e of wedge s.

Figure 70 Butt jointed boards must span acrossminimum 2 bays. Not more than every third boardshould be joined on the same batten.

Avoid differentorientation of annular rings

Figure 69 Butt jointed boards must have similar

orientation of annular rings, and it is an advantageto bevel the cut slightly in order to establish atight joint.

Figure 71 Boards with T&G unsupported butt join ts may be u sed in dwel lings or simi lar.

Unsupported joints may not be used in first and last boar d and not in more than ev ery thi rd boar dwithin the same bay never in neighbouring bays.

Boards and joints of this type must spanacross two bays at least, and not more thanevery third board should be joined on thesame batten, see figure 70.

Boards supplied with T&G in the endsmay be joined without support from

beneath, so-called unsupported butt joints.This type of joints must always be glued.When using boards with T&G unsupported

butt joints, the laying is continued using off cut piece from previous row as starter piecein subsequent row.

End joints within the same bay may onlyoccur in every third board, i.e. there must

be two continuous boards between everyunsupported butt joint, see figure 71.Unsupported butt joints must not occur inneighbouring bays, and no unsupported

butt joints may occur in the first and thelast row. Unsupported butt joints shouldnot be used in floors exposed to loadsexceeding those occurring in dwellings.

FLOORS ON BATTENS51

Wedges

Wooden block fixedto batten withscrews

Batten or joist

Bevelled cut

Butt joint along battencentreline

Board

2 bays Board

No unsupported joints

Unsupported butt jointswith T&G endoints

No unsupported joints 2 bays between buttoints



The last board is designed as shown infigure 72. It is sometimes difficult to fit inthe last board, and to help this problem itmay be expedient to chamfer the upper lipof the groove on the side facing the centreof the board. It is also possible to bevel theside of the board facing the wall. In case thelast board is very narrow it may benecessary to lay the last two boardssimultaneously. They are glue-jointed beforelaying, see figure 73.

In case the supplier recommendsobservation of the 10-board measurement itis required to comply with the saidmeasurement. The 10-board measurementindicates the cover width of 10 boards. The10-board measurement is indicated as aninterval, for example 1293 1298 mmwithin which random check measures of thewidth of 10 boards must fall.

Figure 74 Door with threshold and floor boards perpend icular relative to door openi ng. Notic emaximum joist distance.

Figure 72 Designing the last board.

The last two boardscan be glued /nailed together.

Figure 73 Laying the special-made last board.

Figure 75 Packing of threshold floors withdifferent levels.

The measurement depends on the width of the individual boards, the expected highesthumidity during use, and the chosen woodspecies.

Doors with threshold The floor boards meet under the threshold.There should be a clearance of 20 30 mm

between ends of floor boards in the door opening depending on extend of adjoining floors. When boards are placed

perpendicular to door opening, as shownin figure 74, the joints between the


Maximum. 250 mm

Packing

Wedge-



Figure 76 Floor boards may continue throughdoor openings when the door has no threshold.This solution should only be used in smaller rooms.

Figure 77 Joint covered with metal strip. Thissolution is used when floor boards are positioned

perpendicularly or parallel in relation to each other.

boards should be aligned on either side of the threshold. The floor planes inadjoining rooms should have the samelevel. In case this is not possible, thethreshold should be packed to align it withthe level of the highest floor, see figure 75.

Doors without a threshold In case the doors do not have a threshold it is

possible to let floor boards continue throughthe door opening when the floor boards are

positioned perpendicularly relative to theopening, see figure 76.

When floor boards continue through adoor penning it is required to design thewidth of the joints along walls as if the floor were in one room, measuring the widthfrom wall to wall through the door opening.

When floor boards in one room are positioned perpendicularly relative to floor boards in adjacent room, as shown in figure77, it is required to establish a joint with a

between the two floors. The width of the joint should be 15-20 mm depending on thesize of adjoining floors. If needed, the jointmay be covered with a flat or curved metalcover strip. The strip should one be fixed toone of the floors and must not becountersunk to become flush with the floor surface.

This solution may also be applied incases where the floor boards in bothrooms are positioned parallel to the door opening. In this case the joint will acceptmovements from both floor planes.

Pipe pene trationsHoles for pipes shall have a diameter 20mm larger than the pipe going through thehole in order to allow for the independentmovement of the floor, and in order toensure that there is no contact betweenfloor and pipe.

When floors are fitted after pipeinstallation the hole is cut as illustrated infigure 78. Once the floor board is in placethe cut out block is glued back into

position, and the hole is covered with anescutcheon.

Figure 78 Cutting a hole for pipe penetration. The

wedge has bevelled sides ensuring a tight fit in theopening.


Metal cover strip

Wedge with bevelledsides



Floating floorsFloating floors are normally laid on structuralfloors made of cincrete, lightweight concreteor wood. When laid on concrete or lightweight concrete it is recommendedalways to lay a moisture barrier in order toavoid construction moisture or groundmoisture from entering the floor. Themoisture barrier should consist of minimum0.20 mm PE-foil laid with minimum 200mm overlap at all joints. In case it isrequired to lay the wood floor very soonafter casting the concrete it is required touse a very tight moisture barrier, for example bitumen felt glued to the concreteslab and with airtight joints, see Gluing bitumen felt, page 21.

Underlay and intermediate layer Before laying intermediate layers it isrequired to level the sub floor creating a

plane surface, for example by the use of asmoothing compound. Deviations from

planeness should be less than ± 2 mm whencompared to a 2 m straightedge.

Type of intermediate layer is chosen withconsideration to establishing a reasonablyrigid floor which does not shakeunnecessarily when walked on, and does notcause the inclination of furniture or equipment due to deflection. Maximumdeflection should not be more than be 2.5mm.

The preferred materials for intermediatelayers are: Expanded polystyrene typeEPS 150 or EPS 250, hard mineral wool

batts, porous wood fibre boards, robustgeotextile in more the one layer, foam

plastic sheets with air bubbles and specialmats based on rubber and cork. When usingcompressible intermediate layers likemineral wool and polystyrene, it isrecommended to insert a pressuredistributing board, for example 22 mmfloor chipboard.

The floor planeFloating floors are made in such a way that thefloor constitutes one coherent floor plane able

to move independently in relation to theunderlay. The floor plane may be constructed

with coherent wood or concrete sub floors ontop of which the wood floor is laid out andmaybe glued. The sub floor has a pressuredistributing function and, being so, the floor covering does not need to be a suspendedfloor, but can be made of short stave parquetor mosaic parquet, see figures 79-83

Figure 79 Floating floor constructed with parquetstaves or parquet boards glued onto a wooden

panel laid on a thin intermediate layer

Figure 80 Floating floor constructed with parquetstaves or parquet boards glued onto a wooden

panel which again is laid on hard insulation.


Wood floor Glue

Wood flooring panel

Moisture barrier

Intermediatelayer

Concrete

Wood floor Glue

Wood flooring panel

Moisture barrier

Hardinsulation

Concrete



Figure 81 Wooden floor glued on top of a floatingconcrete slab. Notice that the concrete slab must

be complete ly dry and p lane before glui ng th ewood floor.

Figure 83 Floating floor made with pressuredistributing flooring panels laid on top of hardinsulation. The floor cover is T&G flooring

board s joi ned wit h steel cli ps and la id on a th inintermediate layer in order to reduce clattering.

Figure 82 Floating floor made with pressuredistributing flooring panels laid on top of hardinsulation, The wooden floor (glue-joined woodveneer boards) is laid on a thin intermediatelayer in order to reduce clattering.

Figure 84 Floating floor made with glue-joinedwood veneer floor boards laid on a rigidunderlay, for example concrete, and with a thinintermediate layer, which may function as asound reducing layer and as a moisture barrier atthe same time.

Floating floors may also be constructed bythe use of wood vceneer floor boards or similar laid on a rigid substrate. The boardsare placed on top of a thin sliding layer, for exampe a 0.20 mm PE-foil and/or a cork

sheet placed on the rigid underlay. The ri-

gid underlay could be a concrete slab, awooden sub-floor made of flooring panelslaid on battens or joists etc. The boards are

joined either by gluing in the T&G accordingto manufacturer s instructions or by the use

of purpose-made clips placed in grooves onthe backside of the boards, see figures 84-85.

SV0MMENDE GULVE 55

Glue Wood floor Concrete slab

T&G flooring boards joined with steel clipsIntermediate layer

Wood flooring panelMoisture

barrier

Hard insulation

Concrete

Hard insulationMoisture

barrier

Concrete

Intermediate layer Wood floor

Wood flooring panel

Moisture barrier

Hard insulation

Concrete

Wood floor Intermediate layer

Moisture barrier

Concrete



It is required to supply planks and flooring panels with T&G on all four sides in order to use them as floating floors placed directlyon top of an intermediate layer.

Flooring panels used as sub-floors mustcarry a marking stating approval for use infloor constructions.

The floor palne must not be fixed, i.e.should be able to move freely. It isimportant to observe that there shall be adistance of minimum 10 mm between floor and all surrounding walls and around

penetrating installations, for example pipes,. This distance depends on the size of the floor and the manufacturer srecommendations should always befollowed.

In order to prevent the floor fromcracking it is normal procedure to establishdilatation joints at every 8 m across thewidth of the (perpendicular to graindirection in the wood). It is alsorecommended to establish dilatations jointsin floating floors subject to heavy loads, asfor example in offices with heavy filingcabinets, because the load may prevent thefloor from moving freely. In casedilatations joints are not established theresult may be cracks and chinks in thefloor. The floor may also crack in case theroom is very irregular and in this wayhindering the free movement of the floor.fladen bliver hindret.

Laying a float ing floor The laying instructions described below refer to plank floors in the form of floor boards,wood veneer flooring boards and the like.For the laying of parquet staves, parquettiles or blocks on a floating sub-floor,reference is made to the subsequent sectionabout glued and nailed floors.

The first row of boards is laid with thegroove facing the wall. The boards arealigned by the use of a building line. Adistance of minimum 10 mm between thewall and the board must be established. Inrooms exceeding 6 m measured across thegrain direction in the wood and 12 m alongthe grain direction, the distance shall beincreased in accordance with roomdimension and wood species. Temporarydistance blocks are placed between the firstrow of boards and the wallin order toensure that the boards are not displacedduring the laying, see figure 86.

Figur 86 Laying the first row of boards with thegroove facing the wall and fixed by the use of temporary distance blocks.

Figur 85 Floating floor carried out with floor

board s joi ned wit h c lip s a nd lai d on a rig idunderlay, for example concrete. A thinintermediate layer which may function as a soundreducing layer and as a moisture barrier at thesame time.is introduced between flor andunderlay.

The next row of boards is now placed and the boards are knocked together using ahammering block or a hammering rail. Insome cases the hammering block may simplyconsist of a sawn off piece of board, whereasother porducts may require the use of specialhammering block in order to avoid damagingthe profile (the tongue side of the board)

56 FLOATING FLOORS

T&G flooring boards joined with steel clips

Intermediatelayer

Moisture barrier

Concrete

Distance blocks

Tongue

Groove

Intermediatelayer



The boards are joined by gluing the T&G or by the use of clips. When joining the boardsend-to-end, the T&G must also be glued.The laying continues using the cut- off froma previous row as the starting board in thenext row. Using this principle, the end-to-end joints of the boards will be staggered.End-to-end joints in two neighbouring rowsshall be staggered by minimum 500 mm, seefigure 87,

The last board is adapted as shown infigure 88. It may be difficult to fit in the last

board. The process of fitting the last boardcan be made easier if the lower side theupper lip of the groove is chamfered.

Figure 89 Laying the last board(s)

Figure 90 The last board is knocked into place bythe use of a hammering rail or squeezed into

place by the use of a crowbar.

Figure 87 Placing end-to-end joints of the boards. Avoid closely placed end-to-end jointsin neighbouring rows (zig-zag-pattern).

Figure 88 Tracing the size of the last board.

It is also possible to cut the edge of the board at a slight inward angle on the sidefacing the wall. In case the last board is verynarrow it may be necessary to lay the lasttwo boards simultaneously. In this case theyshould be glue-joined before laying them,see figures 89-90.

In case the supplier recommends that thefloor is laid in accordance with the 10-boardmeasurement, it is required to observe themeasurement requirement indicated. The10-board measurement indicates how widean area 10 boards should cover. The 10-

board measurement is indicated as aninterval, for example 1293-1298 mm, i.e.the covering width of 10 boards shall fallwithin this interval. The measurementdepends on: The width of the boards, theexpected highest air humidity and the floor

product used. .

FLOATING FLOORS 57

The last two boards my benailed/glued together. , Wedge-

Bevelled edge

HammeringrailMinimum 500 mm

Avoid uniform staggering of theboards



Doors with a th reshold The floorboards extend under the threshold.It is required to establish a distance of minimum 20-30 between the floor boardswhere they meet in the door opening depending on the sizes of the adjoining floors.In case the boards are perpendicularl to thedoor opening, as shown in figure 91, the

joints between the borads should be alignedon the two sides of the threshold. The levelsof the floors in adjoing rooms should be thesame. In case this is not possible, the thresholdshould be packed to the level of the highestfloor, see figure 92.

Figure 91 Floating floor with boards perpendicular todoor opening doors with a threshold.

Doors without a threshold It is usual practice to establish a joint

between the two floors where they meet inthe door opening in order to allow for movements caused by humidity changes.The joint can be concealed by the use of aflat or curved metal cover strip fixed inone of the floors only, see figure 93. Thecover strip must not be countersunk intothe floor as this may prevent the freemovement of the floor.

Figure 93 It is usual practice to establish a joint between floor in adjoining rooms, in particular when the floor boards are perpendicular to eachother or when they are paralel to the door opening.

Figure 92 Packing the threshold betweenfloating floors at different levels.

Figure 94 Where there is no threshold, the flooring boards may cantinue through the door opening. Itis, however, recommended to use this method insmaller rooms only.

58 FLOATING FLOORS

FtfstSpter-re

Wooden floor

Minimum 20 mm

Wooden floor Cover strip

Wooden floor

Intermediate layer

Moisture barr ier

Concrete

Intermediate layer

Moisture barr ier

Wooden floor Wooden floor

Wooden floor

Wooden floor

Packing

Intermediate layer

Moisture barrier Concrete

Intermediate layer

Concrete

Moisture barrier



Where there is no threshold, the flooring boards may continue through the door opening, as shown in figure 94.

When boards run through the door opening, it is required to dimension the jointalong the walls in both rooms as if the floor were one floor with a total widthcorresponding to the width of both roomsmeasured through the door opening.

Pipe penetrationsAll holes for pipes shall have a diameter 20mm larger than the pipe going through thehole in order to allow for movements. t.

Around existing pipes it is possible to cutout a V-shaped block shown in figure 95.After placement of the board, the block isglued back into place and covered with a

pipe escutcheon.

Glued or nailed floorsA wide range of wooden floor materialsmay be laid either as glued floors or asnailed floors directly on a subfloor.

The subfloor shall be stable and rigid. Therequirements to evenness and flatness of thesubfloor are equal to same requirements tothe final floor. Deviations from flatnessshall be less than ± 2 mm measured with a2 m straightedge, see Appendix: Flatness.

The subfloor must be without any leveldifferences and there must be no sharp

points. In case the requirements to flatnessare not fulfilled, it is required to adjust theflatness, for example by means of sanding or

by the use of a filler compound.

Nailing/screwing All wooden floors with a tongue and agroove may be nailed or screwed to thesubstrate provided the substrate is suitablefor such fixing for example a new subfloor made of particle board or an existing woodenfloor. Nail and screw dimensions must bechosen in accordance with board thickness,see Fasteners and adhesives. In case thesubfloor is made of particle board, it isrequired to use screws.

Fixing is normally carried out as secretfixing, i.e. by screwing or nailing at an angle -starting at the topside of the tongue (seefigures 97-98). The secret fixing of wood veneer flooring boards with a core of

particle board must not be carried outwithout consulting the manufacturer. Onconcrete subfloors, the fixing may becarried out by screwing directly into theconcrete - see Fasteners and adhesives.

Laying of flooring boards screwing or nailing.The principles applied are similar to those

principles described in the sectionconcerning floors on battens/joists.

The firs row is laid with the groove facingthe wall. The boards are aligned by the use of a building line. A minimum distance of 10mm must be observed between the boardand the wall.

In rooms with dimensions exceeding 6 mmeasured across the boards, and 12 malong the boards, it is required to increasethe distance between the boards and thewalls in accordance with room size.Temporary distance blocks are placed

between the first row of boards and thewall in order to ensure that the boards arenot being displaced during the laying of theremaining part of the floor.

GLUED AND NAILED FLOORS 59

Concrete

Figure 95 Cutting out for a pipe. The V-shaped block is g lued back in to p lace and covered with a pipe escutcheon.

Intermediate layer

V-shaped block



Floor ingboards/screwed fr om top side Boards fixed with visible nails/screws,should be fixed with a screw/nail placedapproximately ¼ board width from thegrooved edge of the board. Boards whichare particularly wide, i.e. 200 mm or more,are fixed with two visible nais/screws inevery board, see figure 96. It is possible toclose the nail/screw holes using wooden

plugs.

Figure 96 Flooring boards nailed or screwed fromthe top side. In case the boards are more than 200mm wid e, they must be fixed with two screws inaccordance with the distances indicated.

Figure 98 Placering og dimensioner paskruer ved fordsskt fastg0relse, f.eks. i beton.

Floor boards scret nailing/screwing The first board is nailed from the top andalso secretly in the the tongue, see figure97. The visible nail in the first board is

placed some 20 mm from the grooved edge

of the board. Brads are countersung with anail puncher, and the holes are filled with afiller. The tongue side of the board is nailedthrough the upper side of the tongue. Nailsare placed at an angle between 45° and 60°in relation to the upperside of the board.

Nails are punched. In some cases it may beadvisable to prebore in order to avoid thesplitting of the wood. A similar fixingmay be carried out using screws, also inconcrete, see figure 98.

When nailing, it is important to blunt the point of the nail in order to avoid splitting.The heah of the nail may be used for

punching the previous nail. In this way thehead will be slightly flattened with anoblong shape.

Slagklods

Figur 99 Brsedderne ban ke s sa mm en me d s lag klods e ller slagjern.

60 GLUED AND NAILED FLOORS

Wood floor

Figure 97 Fixing of the first board and secretnailing of the remaining boards.

Distance blocksTongue

Groove

Min. 10 mm

Intermediate layer

TWood panel subfloor G



smallere pa den ene led. Nar den lange sideaf hovedet holdes parallelt med braettet vedS0mning, reduceres risikoen for flaek-ning.

Vejledende dimensioner for S0m er an-givet i tabel 2, side 17. Der s0mmes mindst

pr. 600 mm, dog b0r der ikke s0mmesnasrmere end 50 mm fra braeddeender, sefigur 96.

Efterf0lgende brasdderaskker laegges, og brasdderne bankes sammen med slagklodseller slagjern. Slagklodsen kan for nogle

produkter besta af et afskaret stykke brast,mens andre produkter krasver, at der anven-des en speciel slagklods for ikke at skade

profileringen, se figur 99.Braeddest0dene (endesamlingerne) skal

limes i fer og not, derimod ma fer og not pade lange sider ikke limes. Lasgningenfortsasttes i de efterf0lgende braedderaskker med det overskydende stykke fra den fore-gaende raekke. Herved forskydes samlin-gerne imellem brasdderne. Endesamlinger ito naboraskker skal vaere forskudt mindst500 mm, se figur 100.

Det sidste braet kan vaere vanskeligt at fa pa plads, men det kan g0res lidt lettere vedat affase den 0verste lasbe af noten pa denside, der vender ind mod midten af braettet.Brsettet kan ogsa afskaeres lidt skrat ned-adtil pa den side, der vender ind mod vaeg-gen. Er det sidste brast meget smalt, kan detvaere n0dvendigt at lasgge de to sidste

brsedder samtidig. De limes sammen indenlasgningen, se figur 101-102.

Anbefaler leverand0ren, at gulvet laeggesefter 10-braetsmal skal det oplyste maloverholdes. 10-braetsmalet angiver, hvor meget 10 braedder skal daskke. 10-braetsma-let angives som et interval, f.eks. 1293-1298mm, som en vilkarlig maling af bred-den pa10 bradder skal falde indenfor. Maletafhaenger af brasddernes bredde, denforventede variation i luftfugtighed under

brug og den anvendte trasart.

Figur 100 Placering at brasddest0d. Undga tastlig-gende, ensartede forskydninger af braddest0d inabobraedder (zig-zag-m0nster).

Figur 101 Lajgning af tilpasset endebrat

Figur 102 Sidste brast slis pa plads med et slagjerneller presses pa plads med et koben.

LlMEDE OG S0MMEDE GULVE 61

Mindst 500 mjg.

Undga-ensartede for-skydningcr mcllcm

braddest0d

De sidste to bradder kanevt. limes/s0mmes sammen Kile-

Skra bagkant -

Slagjern



Limning Ved limning skal overfladerne vaere rene,t0rre og klasbbare, se Befcestigelsesmidler.

Gulvmaterialerne ma ikke vasre vindskas-ve og skal have en helt plan underside, der sikrer en god klasbeflade.

Parketstave uden fer og not ma h0jst vaere300 mm lange. Parketstave med fer og notma h0jst vaere 700 mm lange.

Braeddegulve af massivt trte kan normaltikke limes til underlaget, da det er svaert atfa tilstraskkelig kontakt over hele braedde-laengden og fordi de fugtbetingede bevee-gelser i gulvbrasdderne er st0rre end limenselasticitet.

Lamelbrasdder b0r kun limes til under-laget, hvis leverand0ren anbefaler produktettil formalet og kan anvise en egnet laegnings-metode. Det skal sikres at limen er udfyl-dende og at underlaget er sa plant (dvs.h0jst +/- 2 mm afvigelse pa 2 meter retholtog +/- 0,6 mm pa 0,25 meter retholt), at der kan opnas god kontakt mellem lim og brasd-der pa hele ktebefladen.

Fremgangsmaden er den samme som for S0mmede gulve.

Den f0rste raskke stave laegges med not-siden mod vasggen. Stavene rettes ind efter en snor, sa de ligger pa linie. Der holdesmindst 10 mm af stand til vaeg.

I rum, der er st0rre end ca. 6 m malt patvasrs og ca. 12 m malt pa langs af arernesretning i traeet, skal afstanden til afgraen-sende vasgge etc. 0ges afhasngigt af rum-dimensionen. Der anbringes midlertidigeafstandsklodser mellem den f0rste raskkestave og vasg for at sikre, at stavene ikkeforskubber sig under laegningen, se figur 103.

Skal der limes direkte pa et betonunderlag,henholdsvis et afretningslag, skal restpore-fugten vaere under 65 % RF, nar der males itemperaturintervallet 17-25°C, se figur 104.Er der behov for at lime ved et h0jere fugt-indhold i betonen, ma der indskydes eneffektiv fugtspaare, f.eks. en asfaltpap,mellem underlag og trsegulv, se figur 105.

Figur 103 Lasgning at de f0rste parketstave mednotsiden mod vasggen og fastholdt med afstands-klodser. Stavlasngden skal vadges, sa endest0d inaboraskker forskydes mere end 80 mm.

Figur 104 TriEgulv, f.eks. stavparket, limet direkte pa bet on elle r a fret ni ngs lag. D er s kal va sre sikk er-hed for at betonlaget er tilstrskkeligt plant og t0rt.

62 LlMEDE OG S0MMEDE GULVE

\fstandsklodser

Min. 10 mm

MindstW) mm Not

Lim

Beton Not-Fer

Traguiv

lam

Beton



Figur 105 Tragulv, f.eks. stavparket, limet pa eneffektiv fugtspasrre at f.eks. asfaltpap, nar beton-underlaget er for fugtigt til en direkte montage.Fugtspasrren kan limes til betonunderlaget, hvis

restporefugten er under 85 % RF.Trinlydsisolering

Figur 106 Treegulv, f.eks. stavparket, limet pa ettrinlydsisolerende mellemlag, der igen er limet til

betonunderlag et.

Asfaltpap kan klasbes til underlaget med enacryldispersionslim, f.eks. parketlim eller lim beregnet til limning af PVC-belsgnin-ger, nar restporefugten er under 85 % RF.Asfaltpappens kvalitet fremgar af afsnittetom Underlag, asfaltpap.

Er der behov for et bl0dere gulv eller for trinlydsisolering, indskydes der et mellem-lag af f.eks. gummikork. Mellemlaget limestil betongulvet, og trasgulvet limes til mel-lemlaget, nar limen under mellemlaget er haerdet, se figur 106.

Underlaget b0r vasre sa ensartet og plantsom muligt for at sikre den bedst muligeklcebning. Det kan evt. opnas ved en fuld-spartling af underlaget.

Por0se og stasrkt sugende undergulve af beton, letbeton, anhydrit, gips m.v. skal pri-mes inden limningen pabegyndes. Tilanhydrit skal der anvendes en specialpri-mer, som udover at sikre vedhasftningenhindrer, at fugten i limen skader underlaget.

Gulvmaterialerne fuldlimes til underlaget,idet der anvendes en udfyldende lim efter trasgulvleverand0rens anvisning.

Lasgningen b0r tilrettelaegges, sa alleredelagte omrader ikke betrasdes. Der b0r ikke

paf0res lim pa st0rre arealer, end at la^gningkan ske inden for ca. 15 minutter. St0rrel-sen af arealet afhaenger af rummets fugt- ogtemperaturforhold og af underlagets beskaf-fenhed.

Gulvet b0r belastes, f.eks. med sandssk-ke, for at sikre et tilstraskkeligt pressetryk,indtil limen er hasrdet. Det er saerligt n0d-vendigt langs gulvets kanter.

Limede gulve ma ikke betrasdes, f0r denanvendte lim er haerdet. Normalt vil dettage mindst 24 timer.

Trasgulvet ma ikke afslibes eller overfla-debehandles, f0r stavene er i fuldstaendigfugtma^ssig balance efter nedlaegningen.Det kan tage op til 7 d0gn.

LIMEDEOG SOMMEDE GULVE 63

TrcSgulv

Lim

Lim

Beton Asfaltpap

Tr«gulv

Lim

Lim

Beton



Lcegning af parketgulve med enkeltstaveParketgulve udf0rt af enkeltstave kan lseg-ges i mange forskellige m0nstre, f.eks. sil-deben, hollandsk m0nster og fletm0nster.

M0nsterIaegning er mere kompliceret endandre former for laegning. Starten af rn0n-sterlaegningen kraver saerlig stor papasse-lighed, fordi resten af laegningen afhaenger af, at de f0rste stave ligger helt korrekt, sefigur 107-110. Til m0nstergulve kan der leveres h0jre og venstre stave samt special-elementer, f.eks. firkanter og smalle lister iforskellige traearter. Ved de mere komplice-rede m0nstre skal der tildannes specielle

passtykker pa stedet, hvilket kraever stor handvaerksmaessig kunnen og specialvaerk-t0j. Ncermere oplysninger om udf0relse af forskellige m0nstre fas hos parketleveran-d0ren.

Parketgulvet skal afslibes efter laegnin-gen, se figur 11 l.Omfanget varierer efter stavenes kvalitet og b0r aftales med leve-rand0ren ved valg af parketgulvet.

Figur 108 Paf0r kun lim til en stavrjekke ad gan-gen. Saet stavene ned i limen sa tst ved nabostavenesom muligt, og pres staven fast og op mod nabosta-vene, uden at der kommer li m op i fugen.

Figur 107 Laegning af enkeltstave i sildebensm0n-ster. Marker midterlinien i rummet og a fsEet enarbejdslinie en trediedel stavbredde til h0jre herfor.AfsEEt styrelinier vinkelret pa arbejdslinien med enstor vinkel. En krydsfinerlaere g0r det nemmere at

placere stavene vinkelre t mod h inanden.

Figur 109 Tilpasning af stave mod vaeg


Lim

Krydsfiner-skabelon

utirnStyielinie

Styrelinia

Lim

Arbejdslinie

Midterlinie irummet



Figur 110 Udlasg sandsskke pa stavene for atetablere et tilstekkeligt pressetryk, indtil limen er haerdet - isEer langs kanterne.

Lcegning af mosaikparket eller parket-ruder Gulve af mosaikparket eller parketruder bli-ver smukkest, hvis m0nstret er anbragtsymmetrisk pa. gulvet. Derfor opmales gul-vet f0r udlaegningen, sa antallet af heleruder i hver retning kan bestemmes. Denresterende laengde deles med to og angiver,hvor store tilpasningsstykkerne ved vaegge-ne skal vasre. Hvis tilpasningsstykkerne bli-ver mindre end en halv rude, lasgges enhalv rudebredde til og m0nstret gar sa sta-dig op, se figur 112-114.

Ved lasgning kan der f.eks. gas frem paf0lgende made: Hj0rnet af den f0rste helerude males ind. Herfra anbringes og fastg0-res to retholter i en vinkel pa n0jagtig 90°langs de to vasgge. Den f0rste rude lasgges

pa plads, og herefter lasgges en rakke ruder langs hvert af retholterne. Den sidste rude ihver raskke tilpasses og fastg0res. Rudernedrejes i forhold til hinanden, sa fiberretnin-gen skifter fra rude til rude. Ruderne slassammen med lette slag med en slagklods,sa hverken rude eller vinkel forskydes.Lasgningen af de resterende ruder foregar diagonalt over gulvet.

Figur 11 1 Trsgulvet afslibes og overfladebehand-les, nar limen er hasrdet, og gulvet er i fuldstsndigfugtmaessig balance med omgivelserne.

Figur 11 2 Paf0r kun lim pa et sa be greenset om-rade, at rudeme kan lsgges indenfor ca. 15 min.Lceg ruderne fra midten at rummet, skiftevis i defire gulvfelter, ud mod vajggene.


Lim



Figur 113 Lasgning af parketruder og mosaikpar-ket. Mosaikparket, hvor stavene er l imet sammenkant mod kant, knaskkes inden lasgningen i de gen-

nemgaende fuger, sa der fremkommer fire kvadrater kun holdt sammen af bagbekla^dningen. Afsast tomidterlinier i rummet vinkelret pa hinan-den og l»get antal mosaikparket eller parketruder fra rummetsmidte og ud til alle fire sider. Tilpas sidste rude vedvaeg.

D0re med bundstykkeGulvet f0res ind under bundstykket. Der skal vasre 20-30 mm afstand mellem sta-vene i d0rabningen afhaengig af de sam-menst0dende gulves st0rrelse. Ligger stave-ne vinkelret pa d0rabningen, som vist pafigur 115, b0r fuge ligge ud for fuge pa deto sider af bundstykket.

Figur 11 4 Udlaeg sandsa^kke pa ruderne for atetablere et tilstraekkeligt pressetryk, indtil limen er hasrdet - iseer langs kanter.

Figur 115 Limede gulve lagt vinkelret pa d0rab-ning ved d0re med bundstykke.

66 LIMEDE OG SOMMEDE GULVE

Midterlinie

Midterlinie

Stor vinkel

Traegtuv

Linj Beton



Gulvfladerne i to tilst0dende rum b0r liggei samme h0jde. Er dette ikke muligt, op-klodses bundstykket svarende til det h0jestliggende gulv, se figur 116.

D0re uden bundstykke Normalt udf0res der en fuge mellem gulv-fladerne i to sammenst0dende rum, sa fugt-udvidelser kan optages. Fugen kan f.eks.daekkes af en flad eller buet metalskinne,

som kun ma fastg0res i det ene gulv. Skin-nen ma ikke nedstemmes og g0res planmed gulvfladen, da det kan hindre bevasgel-ser i gulvfladen, se figur 117.

Ved d0re uden bundstykke, hvor staveneligger vinkelret pa abningen, kan staveneeventuelt forl0bes gennem abningen mel-lem to mindre rum. Vter dog opmaerksom

pa, at afstanden til vaegge og andre faste begrasnsninger skal ti llade de n0dvendigefugtbevaegelser i gulvfladen i begge rum.

R0rgennemf0ringer Huller for r0r skal udf0res 20 mm st0rreend r0rdimensionen, sa gulvet har mulighedfor at bevasge sig uden at komme i kontaktmed r0ret.

Ved eksisterende r0r saves der ud i brasd-derne som vist pa figur 118. Nar brasttet er

pa plads daskkes udskasringen med en r0r-roset.

Figur 1 1 7 Norma lt u df0r es der en fuge mell emgulve i to sammenst0dende rum, isser nar gulveneligger vinkelret pa hinanden eller parallel! medd0rabningen.

LIMEDEOG SOMMEDE GULVE

Trseeulv /Opkjedsiiing

Lim

Beton

Figur 11 6 Opklodsning at bundstykke ved limedegulve i to niveauer.

Jiflegulv .^

Mjatfiskinne

LimBetpn

Lim

Frasgulv

Figur 11 8 Udskaering for r0r i limede gulve



Lcegning af klodsgulve ved limning Klodsgulve laegges bedst pa et undergulv af trasplader, der mindst b0r have samme tyk-kelse som traeklodserne. Klodserne lasggesmed gennemgaende fuger i klodserneslasngderetning, se figur 119-121. Tvaerfu-gerne skal vaere i forbandt, se figur 119-120. Der skal holdes mindst 20 mm afstandtil vasgge, r0r mv., sa gulvet kan svinde ogkvaslde (udvide sig) uhindret, se figur 121-122. Det bedste resultat opnas normalt, nar de gennemgaende fuger er parallelle medrummets korteste vaegge.

F0r lasgning b0r limleverand0ren tagesmed pa rad ved valg af limtype.

Klodserne fuldklaebes til underlaget, sefigur 121-122. De laegges side om side ilimlaget og ma ikke skubbes sammen, efter at de er nedlagt, idet der herved kan presseslim op i fugerne. Dette vil normalt medf0re

problemer med brud i fugerne ved fugtbe-vasgelser i gulvet, fordi klodsernes mulig-hed for at udvide sig individuelt hindres.

Lcegning af klodsgulve pa betonLimning af traeklodser anbefales ikke af alleklodsleverand0rer, idet der kan vaere

Figur 11 9 Lsg klodserne rigtigt og i forbandt -splintside mod splintside - marvside mod marvside.

risiko for vedhasftningssvigt, fordi forbe-handlingen af betonoverfladen er kraevende.F0r laegning skal betonen vasre t0r, dvs.med en fugtighed under 65 % RF. Det gasl-der ogsa afretnings- og spartellag, der sam-tidig skal have tilstraekkelig styrke.

Figur 120 La;gning af klodsgulve. Afsaet rummets midterlinie samt et antal styrelinier vinkelret herpa. L<Egklodserne i forbandt f'ra rummets midte og ud mod vajggene.


Midterlinie

VinkelStyrelinie

Trasgulvplade



Figur 122 Udskeering for r0r i limede klodsgulve

Ved anvendelse af por0se, selvnivelerendeafretningslag, f.eks. anhydrit, skal overfla-den vaere slamfri og grundig primet.

Hvor der kan vaere risiko for opstigendefugt, f.eks. pa terraendask, skal betonlagetvaere forsynet med en fugtspaerre. Vedanvendelse af flydende fugtspasrrer, f.eks.epoxybaseret, skal den anviste paf0rings-tykkelse overholdes, for at der opnas enfugtspaerrende virkning.

F0r lasgning b0r leverand0ren tages med pa rad ved valg af primer, grander, fugt-spaerre og limtype.

Beton- eller afretningslag primes, og der fuldspartles f.eks. med en selvnivelerendespartelmasse, sa der opnas en helt planflade uden ujasvnheder (+/- 2 mm malt pa 2m retskede). Efter t0rring maskinslibesoverfladen sa den er fri for grater, overgan-ge og slam. Herefter grundes overfladenf.eks. med parketlim i forholdet 1:2. Nar grundingen er t0r lasgges klodserne som

beskrevet ovenfor.

O verfladebehandling Tidligst to d0gn efter nedlaegning foretagesen total afslibning af overfladen. Alt slibe-st0v fjernes og gulvet overfladebehandlesf.eks. med gulvolie efter leverand0rensanvisning.

Lcegning af klodsgulve i sand Klodsgulve kan ogsa laegges i et 20-30 mmtykt lag afrettet sand med sandfyldte fuger.Denne metode giver mindre sikkerhed modforskubninger imellem klodserne som f0lgeaf mekaniske pavirkninger eller af fugtbe-veegelser i gulvet. Til gengaeld er der st0rremulighed for at foretage aendringer eller reparationer, og klodserne kan genbruges.Klodserne b0r vaere mindst 80 mm tykke.

Ved klodsgulve skal der veere en fri af-stand til vasgge, r0r mv. pa mindst 20 mm.

Kvaliteten af det anvendte sand fremgar af afsnittet Sand, se side 16.

Gulvet b0r kun reng0res ved fejning.


"frasklodser

Fwgtsparre

LimMellemlag Tragulvplade

Figur 121 Klodseme sasttes i limen taet ved nabo-klodseme og presses ned i lirnen taet til naboklod-serne, uden at der presses lim op i fugerne.

Trasklodser

Lim

Thegulvplade MeHemlaa. buss pea' ft)



R ENOVERING

Ved renovering stilles de samme krav tilunderlaget som ved Isegning af nye tras-

gulve. Det skal have den forn0dne styrke ogstivhed, samt vaere fast, t0rt og plant, sa der kan opnas et tilfredsstillende resultat.Gamle gulvbelaegninger som linoleum ogtaepper b0r derfor fjernes, hvilket ogsa b0r foretrakkes af indeklimamasssige og hygi-ejniske arsager. Eksisterende trasgulve, der skal danne underlag for et nyt, skal omn0dvendigt efters0mmes, sa det ligger heltfast.

Ved Icegning afbrcedder pa eksisterendeunderlag, kan det vaere n0dvendigt at retteunderlaget op, sa det opfylder de aftaltekrav til planhed og vandrethed. Normalt

kraeves det, at gulve er vandrette, og at afvi-gelser fra planned ligger inden for ± 2 mm pa et 2 m retholt og ± 0,6 mm for et 250 mmretholt. Ved renoveringsopgaver kan det ivisse tilfaelde vaere forbundet med storevanskeligheder og omkostninger at opfyldedet ene eller begge disse krav pa grund af sffitninger, deformationer eller trasbjielker,der »ha?nger« forskelligt. Det b0r derfor aftales pa forhand, hvilke krav der i denaktuelle renoveringsopgave stilles til vand-rethed og planhed.

Opretning kan ske ved spartling og for brasddegulve desuden ved afslibning eller

udlaegning af masonit- eller spanplader.Ved opretning af et eksisterende bjaslke-lag, ma der pafores mindst 45 mm tykke

bradder ovenpa eller pa siderne af de gamle bjaelker, sa der er et tilstrakkeligt underlagfor s0m eller skruer, se figur 126.

Nye brceddegulve som s0mmes ovenpagamle brajddegulve lasgges med samme

bradderetning som de gamle. S0mning skalske i bjaslker eller str0er og ikke i brasdder.

Sv0mmende traegulve udlasgges med for-del pa tvcers af et eksisterende trasgulv, sefigur 123-125. Meget tynde traegulve

Figur 124 Lasgning at nyt traegulv med et trinlyds-isolerende mellemlag pa et eksisterende gulv. Bund-stykket heeves evt. ved en opklodsning.

(10-14 mm) vil i visse tilfaelde kunne giveuens fjedring af gulvet. Dette skyldes, at

basreevnen af undergulvet varierer fra stedtil sted, og at samlingerne mellem de tynde

brasdder kun har ringe stivhed pa tvasrs.Undergulve afbeton skal vtere t0rre. Hvis

der males porefugt pa over ca. 65 % i gamleterrsendask, krybekaslderdaek eller kaeldergulve af beton, b0r det unders0ges,om der kommer fugt nedefra, f.eks. opsug-ning af jordfugt i terraendask pga. manglen-

70 RENOVERING

Nyt tfxgulv

M eitem lag

Eksisterendekonstruktion

Figur 123 Leegning at nyt traegulv pa et eksisteren-de asldre gulv.

rrinlyds-isolering

Nyt Trsegulv




de fugtspaerre. Udlasgning af diffusionstaetteeller fugtf0lsomme lag i konstruktioner,hvor der kan forekomme fugttilf0rsel nede-fra, kan resultere i skader, f.eks. limslipeller deformationer af trasgulvmaterialet.Inden et nyt traegulv lsegges, skal kon-struktionen vasre sikret med en fugtspasrre,som beskrevet i afsnittet om Fugttekniskekrav, se side 26-29.Figur 126 Opretning af eksisterende bjaslkelag ved

pafor ing pa siden af bjaslkerne. Ved paforing pa

begge s ider kan und erst0tnin gsafstanden reduceres .

AfslibningGamle trasgulve renoveres ofte ved enafslibning, der fjerner slidt og misfarvetoverflade pa gulvet, f.eks. gammel lak. Seogsa TRM 47, Trcegulve 2.

Der afslibes f0rst diagonalt med groftslibepapir. Nar gulvet er jaevnt, mellemsli-

bes med finere slibepapir pa langs ad gulvbrasdderne. Der st0vsuges mellem hver slibning. Der afsluttes med en finslibning.

I hj0rner, ved fodpaneler og under radia-torer, hvor gulvslibemaskinen ikke kankomme til, anvendes en speciel kantsliber med rund, roterende slibeskive. Hvor kant-sliberen ikke kan komme til, bruges et skra-

bejern og en deltapudser.Gamle gulve med tykke lak- eller fernis-

lag paf0res et tyndt lag gulvslibningsoliefor at hindre, at lakken sastter sig fast i sli-

bepapiret under afslibningen.

Fuger Renovering af asldre trasgulve med fugningaf eksisterende fuger med fugemasse kraever n0je vurdering og planlaegning. Det er n0d-vendigt med en grundig rensning af fugen,hvilket bedst sker ved frassning med over-frasser. Er gulvet olie- eller ludbehandlet,anbefales det at udf0re en pr0vefuge, indenfugearbejdet ivaerksaettes. Pr0vefugen vur-deres for vedhasftning og forenelighed,typisk efter 8 dages hasrdning. Det anbefa-les at radf0re sig med en fugemasseleveran-d0r for en vurdering af l0sningens egnethed.

Fugeskader Skader i fugemassefuger kan vaere vedhasft-ningssvigt som f0lge af uforenelighed mel-lem fugemasse og traesort eller st0rre bevas-gelse end den udf0rte fuge er i stand til atoptage. Disse fuger udskiftes ved udskas-ring, afrensning, primning og fugning, somfor nye fuger. Vasr opmasrksom pa, at reno-verede fuger ikke kan opna samme udseen-de som nye fuger. Ved udskiftning af fuge-massefuger kan det vasre n0dvendigt atefterslibe gulvet.

RENOVERING

IJaforing af hardt tras ^

Nyt ffasgulv

Tririlyds-lSoJering


Figur 125 Lsgning af nyt trasgulv pa et eksiste-rende gulv - med et trinlydsisolerende mellemlag.Bundstykket pafores lister af hardt tras.

Paroiijjg pa Bpefker




S KADER OGAFHJ / ELPNING

Partielle reparationer Afgrasnsede skader, f.eks. pa et enkelt braeteller en enkelt parketstav, kan udbedres ved

partiel reparation eller udskiftning.

Brcedderpd str0er eller bjcelkelag For brasdder lagt pa str0er eller bjcelkelagsaves det skadede brast igennem i to langs-gaende og to tvasrgaende spor, der lasggesca. 20 mm fra kanterne. Der anvendes enrundsav, hvis dybde stilles sa den passer til

brasddetykkelsen. Herefter kan midter-stykket fjernes, idet det dog kan vaere n0d-vendigt at l0shugge stykket med et stemme-

jern pa grund af det runde savspor. Dernasstfjernes de resterende stykker med stemme-

jernet, og limrester i not og fer pa nabo- brasdder afrenses. Et nyt brast tildannes isamme materiale og dimensioner, og under-lasben af noten afskaeres. Pa undersiden af det tilbagevaerende bracts ferside fastlimesca. 80 mm brede stykker af 12 mm krydsfi-ner eller lignende som underst0tning for detnye brast. Krydsfineren skal spasndes mod

brasttet til limen er haerdet. Dernasst paf0reslim pa. underst0tningen og brasddernes fer og not. Endelig lasgges det nye brast ned vedat f0re dets fer ind i noten pa nabobrast-tet,hvorpa brasttet vippes ned pa plads, se figur 127.

Ved brasdder med fer og not pa alle firesider ma feren i enden afsaves. Ved flyve-st0d ma begge ender underst0ttes med pali-met krydsfiner eller lignende pa. sammemade som pa brasttets langside. Limsamlin-gen skal belastes indtil limen er hasrdet.Dernasst slibes brasttet ned, sa det er iniveau med nabobrasdderne. Ved skader paenkelte parketstave kan midten af stavenfrasses vask med en overfrasser. Der frassestil ca. 2 mm fra stavkanter. Resten af stavenfjernes med et stemmejern.

Figur 127 Udskiftning af beskadiget brast pa str0er eller bjslkelag. Der indsasttes en forstsrkning af krydsfiner mellera str0erne, som det nye brast limesfast til.

Limede gulveLimede gulve med stave uden fer og notkan repareres med en ny stav, der nedlimesdirekte.

For stave med fer og not fjernes feren pastavens ende og underlasben af noten. Sta-ven lasgges ned ved at f0re feren ind i noten

pa nabostavens langside, se figur 128. Lim-samlingen skal belastes, indtil limen er hasrdet. Dernasst slibes staven ned, sa den er i niveau med nabostavene.

For lamelparket findes der reparations-stave, som tillader udskiftning af enkelt-stave i slidlaget, men ofte vil en udskiftningaf et helt brast vasre det mest veleg-nede.Figur 128 Udskiftning af beskadiget parketstavlimet til underlaget. Staven belastes indtil limen er

hasrdet.

72 SKADER

Gulvbrat ud^nunderlsbe i nc ten

LimKrydsfinerlaske

Lim. Parketstav uden-underleebe i no



KnirkenDe fleste problemer med knirkende gulveskyldes, at traeet i bjaelker eller str0er har vasret for fugtigt ved lasgningen. Proble-merne kan derfor i vid udstraskning undgasved at berrytte t0rt tras. Knirken kan opsta,nar traeet svinder ved udt0rringen, sa der

bliver et mellemrum mellem str0 og brast.Knirkelyden opstar ved, at brsedderne vedfaerdsel pa gulvet bevasger sig op og ned iforhold til s0mmene.

Knirken fjernes ved at presse brasddernened pa underst0tningen, og efters0mmeeller skrue brasdderne fast. Eventuelt kandet i f0rste omgang vasre tilstraekkeligt at

banke de eksisterende s0m laengere ind, vedat anbringe en stor hardttrassklods pa gul-vets overside, og banke pa den med en klap-hammer.

Knirken kan ogsa skyldes, at gulvet er maskins0mmet fordaskt med f.eks. trads0mog ikke presset tilstraekkeligt hardt ned pastr0er eller bjaelkelag. Gulvbrasdderne hvi-ler herved pa trads0mmene. Det giver an-ledning til knirkelyde mellem s0m og gulv-

brasdder, fordi brasdderne ikke ligger fast tilunderlaget.

Knirken forekommer ogsa, hvor lamel-gulve med spankerne s0mmes fordaskt,fordi s0mmets vedhasftning i den bl0despankerne er for ringe. Knirkelydene af-hjaslpes bedst med efters0mning oppefra.

Til efters0mning oppefra af gamle, knir-kende trasgulve pa str0er eller bjaelkelagskal der anvendes ringede, spiralsnoede

gulvs0m, f.eks. 3,5 x55 mm for 20-22 mm brasdder, og 3,8 x 65 mm for 25-28 mm brasdder. Efters0mning b0r f0rst ske, nar der er sikkerhed for, at bJEelkerne fugtmass-sigt er i ligevasgt med fugtindholdet i byg-ningen. Ved fordaskt S0mning kan str0- eller

bjaslkeplaceringen som regel findes ved at banke pa gulvet eller ved hjaslp af en metal -s0ger.

Knirken kan ogsa skyldes svigt i underla-get, enten pa. grund af at nogle opklodsnin-ger har forskudt sig, eller fordi str0- eller

bjajlkelaget ikke er ordentligt afrettet. Efter et stykke tid vil der kunne opsta en afstandmellem braeddeme og de str0er eller bjselker,der har sat sig. Dette medf0rer, at brasdder-ne kan bevasge sig i forhold til S0mmene, sagulvet knirker og opfattes som eftergiveligt.

Der er ingen sikre metoder til udbedringaf svigt i str0- eller bjaelkelag. I nogle til-faelde kan der opnas en acceptabel udbed-ring, ved at str0en og brasdderne traskkestset sammen med skruer oppefra.

Der findes specielle skruer med groft,selvskasrende gevind beregnet til udbedringaf str0konstruktioner, hvor underst0tningensvigter. De skrues ned igennem str0en, hvor de laver et gevind. Ved at justere skruen kanstr0en hasves og sasnkes, sa den lokalt over-tager underst0tningens funktion, se figur 129.

Ved brug af specialskruer skal man vasreopmasrksom pa ikke at beskadige r0r ogkabler, som kan vaere f0rt under gulvet.

Ved skader af st0rre omfang kan udbed-ring kun ske ved omlsegning af gulvet ogopretning af underlaget.

Figur 129 Gulv-Jack skrue kan anvendes, hvor op-klodsningen svigter lokalt. Spasnd ikke for hardt sagulvet bliver hcevet.

SKADER 73

Trasgulv - Traprop

Str0

-Gulv-Jack skrue



Figur 130 Tvsrkrumme brasdder - vaskebrcet -skyldes som regel fugt pa brfeddemes underside.

Tvasrkrumme braedder LiEgges traegulve pa et fugtigt underlag, vil

bagsiden blive opfugtet og udvide sig. Detkan vise sig som blivende deformationer iform af tvaerkrumme brasdder, der normaltgar under betegnelsen vaskebrcet, se figur 130. Vaskebrset kan undgas ved at s0rge for,at underlaget er t0rt, eller ved at der anven-des en fugtspasrre. Er der tale om bygge-fugt, kan skaden eventuelt afhjaslpes ved enafslibning af gulvet, nar der er opnaet fugt-ligevasgt i bygningen.

Ved opstigende grundfugt vil det normaltvaere n0dvendigt at indskyde en fugtspasrrefor at hindre yderligere fugttilf0rsel og engentagelse af problemerne. Det betyder, atgulvet ma laegges om.

Vaskebrcet kan ogsa optrade, hvis gulvbrasdder nedlaegges med et fugtindhold pa.12-17 %. Ved senere udt0rring til 6-8 %fugtindhold vil braedderne t0rre hurtigst paoversiden og blive tvasrkrumme.

Tryksvind og udvidelsestrykHvis et traegulv opfugtes efter laegningen,kan det fa en betydelig fugtudvidelse, der kan medf0re problemer. Bliver braedderneforhindret i at udvide sig, f.eks. ved at dest0der mod en s0jle eller en vasg, vil celler-ne i traset blive presset sammen, og braed-derne vil blive synligt smallere ved senereudt0rring. Dette fsenomen betegnes tryk-svind.

Hvis kraefterne bliver for store, vil gulvetenten bule op, hvilket normalt vil ske for sv0mmende gulve, eller det kan i vaerstefald skubbe vaeggene ud.

Hvis et trasgulv af fyrretras med ca. 10 %fugtindhold netop ber0rer f.eks. omgi-vende vaegge, er det tryk, det kan ud0veved opfugtning under brug, ca. 2,5 N/mm 2

1radial retning og ca. 1,5 N/mm 2 i tangential retning. Anvendes et gennemsnit pa2N/mm 2 vil et 22 mm brast kunne levereet tryk svarende til 2 x 22 x 1000 N/lbm «ca. 4,4 ton pr. meter.

Udbedring af skader efter fugtudvidelser bestar i at friskaere langs de kanter, som er forhindret i at bevasge sig. De aestetiskeskader som bestar af revnedannelser er van-skelige at udbedre med et godt resultat. Vedmindre skader kan en afslibning vasre til-straskkelig, ellers vil det normalt vaere n0d-vendigt at lasgge gulvet om.

Revnedannelser Ved udt0rring vil trasgulve svinde, og der vil naturligt komme fuger mellem braedder og stave. Hindres det fugtbetingede svind,kan det resultere i kraftige partielle revne-dannelser, idet de spasndinger der opstar itraset ofte udl0ses ved de svageste steder.Svindet koncentreres ofte i enkelte fuger eller i enkelte bradder. Revner far en sam-let bredde svarende til hele gulvfladenssvind. Det er et udbredt problem ved sv0m-mende gulve, som er fastholdt af tunge

belastninger fra inventar, s0jler eller hardeog stasrkt klaebende fugemasser, der ofte er udf0rt uden harftebrydende bundstop ifugens bund.

Afhjffilpning kan eventuelt ske ved at ind-lasgge en dilatationsfuge i revnen. Indlasg-ges dilatationsfuger fra starten, er detmuligt at planlasgge, hvor gulvet skal kunne

bevasge sig, og hvor brede fugerne skallaves.

74 SKADER



A PPENDIX

FugtmalingFor at kunne vurdere de fugtmasssige for-

hold, f.eks. byggefugt, forud for l<egning af trasgulve eller for at fastlasgge skadesarsa-ger, er det n0dvendigt at kunne male fugt.Maling af fugt i forbindelse med taegulveomfatter maling af relativ luftfugtighed,maling affugt i undergulve, isaer beton ogletbeton, og maling affugt i trcematerialer. Idet f0lgende er der givet en kort omtale af nogle almindeligt anvendte metoder. Enmere uddybende gennemgang af metoder findes i SBI-anvisning 170: Mdlemetoder til bygningsunders0gelsei; GSO Gulvfakta ogdiverse standarder.

Der skal ved fugtmaling ofres opmasrksom-hed pa l'0lgende forhold:

Brugeren skal vasre fortrolig med detanvendte instrument og skal vasre i standtil at vurdere resultatetBygningsfysisk viden er en forudseetningfor tolkning af resultater udover alminde-lig kontrol af fugtindholdetFugtforholdene i en konstruktion kanvariere betydeligt fra et omrade til etandet, og derfor skal der som oftest fleremalinger til for at give et ordentligt bille-de af forholdeneMalingerne b0r forega tilstraekkeligt

lsenge, sa man er sikker pa, at der er taleom en ligevaegtstilstandFugtforholdene kan variere betydeligtover aret, og vurdering af resultater b0r tage hensyn til dette

Maling affugtvariationer i underlag -kapacitiv fugtmdler Maleinstrumentet, der er billigt og nemt atanvende, anbringes direkte pa overfladen af det materiale, der skal pr0ves, se figur 131.Ved maling vises resultatet som en male-va?rdi, der er afheengig af fugtindholdet.

Figur 131 Fugtf0ler - kapacitivfugtmaler - er egnet til at finde forskelle i fugtindhold.

Kapacitive fugtmalere egner sig ikke tilmaling af absolut fugtindhold udtrykt i %.Derimod er de velegnede til at finde for-

skelle i fugtindhold, f.eks. til at lokaliseresasrligt t0rre eller Scerligt vade omrader idet gulv, der skal unders0ges. Maleren er ikke-destruktiv, idet der males pa trasetsoverflade med en maledybde pa op til 35mm.

I Appendix: Fugtmaling i beton er der givet en lidt fyldigere forklaring pa frem-gangsmaden ved lokalisering af vade ogt0rre omrader i undergulve af beton. I0vrigt henvises der til GSO Gulvfakta.

Maling affugt i beton og letbeton relativluftfugtighed i borehul Den almindeligst anvendte metode til ma-ling af fugt i beton er at male luftfugtighe-den i et borehul i betonen. Der bores nor-malt til en dybde svarende til 0,4 x tykkel-sen af betondaskket. Efter st0vsugning af hullet anbringes en f0ler i hullet, og der tastnes, sa f0leren kan komme i ligevasgtmed den relative luftfugtighed i det bo-redehul - og dermed ogsa med fugten imaterialet. Det vil normalt tage fra mange

F UGTMALING 75



Figur 132 Elektronisk fugtmaler til maling af rela-tiv luftfugtighed og relativ luftfugtighed i borehul i

beton eller letbeton.

timer til flere dage inden ligevasgt er ind-tradt, se figur 132 og 136.

Alternativt kan der udtages pr0ver, somanbringes i plastbeholdere med tastsluttendelag, hvori malinger senere kan foretages.Udtagning af pr0ver skal ske ved udhug-ning, idet vand eller varme, f.eks. fra envandk0let boremaskine, kan medf0re mis-visende resultater.

Maling af relativ luftfugtighed med psykrometer Med psykrometret kan der foretages en 0je-

bliksmaling af luftfugtigheden. Der benyt-tes to prEecisionstermometre hvoraf det eneer overtrukket med en vad bomuldsstrfimpe.Luften bringes til at str0mme forbi termo-metrene, hvorved der sker fordampning fra

strfimpen og derved afk0ling. Afk0lingensst0rrelse - dvs. forskellen mellem tempera-turen malt med det vade og det t0rre termo-

meter er et udtryk for den relative luftfug-tighed. Metoden er forholdsvis n0jagtig og

benyttes ofte til kalibrering af andre male-instrumenter, f.eks. termohygrograf.

Maling af temperatur og relativ luftfug tighed med termohygrograf En termohygrograf bestar af et bimetalter-mometer og et hygrometer i form af en har-harpe. Begge dele er forbundet til en pen,som indtegner malevEerdierne pa en lang-somt roterende tromle forsynet med et styk-ke malepapir. Tromlen drejer en omgang il0bet af en bestemt tidsperiode, som nor-malt er en uge. Derved fas en registeringaf, hvordan luftens fugt og temperatur har varieret.

Som alle hygrometre krasver harharpenregenerering og kalibrering med forholdsviskorte mellemrum, hvis der skal opnas

palidelige resultater, jf. SBI-anvisning 170.

Maling af temperatur og relativ luftfugtighed med data-logger Data-loggere er en forholdsvis ny typeinstrumenter til maling af temperatur ogrelativ luftfugtighed, se figur 133. De be-tjenes via en pc og kan programmeres til

76 FUGTMALING

Figur 133 Datalogger til maling af temperatur ogrelativ luftfugtighed.



at male i varierende tidsperioder, fra fa mi-nutter til mange maneder. Maling og data-opsamling sker ved hjaslp af et lille elektro-nisk instrument, og der kraeves ingen led-ninger under malingen. Efter malingenindlffises data pa pc'en, hvor ogsa videre

behandling kan ske.

Maling af trceets fugtighed med elektrisk modstandsmaler (stikbensmaler)Den almindeligste metode til fugtmaling itra; pa byggepladsen er elektrisk mod-standsmaling mellem to elektroder, somstikkes ind i traset, se figur 134. Metoden er

baseret pa, at modstanden mellem elektro-derne er afhasngig af traets fugtindhold.Der findes mange fabrikater, men kun tohovedtyper af instrumenter. Den ene typehar isolerede elektroder, sa der kun malesved spidsen af elektroderne. Dette kan vaereen fordel, fordi der ikke sker forstyrrelser,f.eks. pa grund af kondens pa overfladen.Den anden type instrumenter har uisoleredeelektroder og er som regel billigere ognemmere at arbejde med.

Der skal males pa langs ad arerne og ikkehenover revner og knaster eller i nasr-hedenaf s0m eller skruer. Malinger skal foretagesmindst 300 mm fra endetrae, og der malesnormalt mindst tre steder, se figur 135.

Fugtindholdet i gulvbradder b0r males i begge ender af brasdderne, da densiteten itop- og rodende varierer. Det betyder ofte, atder er forskelligt fugtindhold og udt0r-ringstid i de to ender.

De fleste instrumenter angiver direktefugtindholdet i %. Normalt er instrumenter-ne kalibreret til at male i fyr og gran, og der ma korrigeres ved maling i andre materia-ler, ligesom der ma korrigeres ved tempera-turer, der afviger vaesentligt fra 20°C.

Da trykimprasgneringsmidler kan asndretraeets ledningsevne, vil malinger i trykim-

prasgneret tra give misvisende resultater.

Figur 134 Elektrisk modstandsmaler til maling af traeets fugtighed.

Figur 135 Der males pa langs ad arerne og mindst300 mm fra endetras.

F UGTMALING 77



Fugtmaling i betonF0r lffigning af traegulve pa underlag af

beton, letbeton og lignende skal man sikresig, at der ikke er fugt i undergulvet, somkan skade traegulvmaterialerne. Frem-gangsmaden ved udf0relse af fugtmaling i

betonunderlag er kort omtalt her. En mereudf0rlig gennemgang findes i GSO Gulv-

fakta.

FremgangsmadeGulvet opdeles i et modulnet, saledes at der inden for hver maske i modulnettet er ca. 10m2. Der males f0rst med et ikke-destruk-tivtmaleudstyr, f.eks. en kapacitiv fugtma-ler, ihvert skaeringspunkt i modulnettet for atfastlaegge de fugtigste og de t0rreste ste-der. Dernaest males med udstyr til maling af relativ fugtighed i et antal borehuller, sefigur 136.

Der males i de fugtigste, de t0rreste og denormale omrader. De normale omrader skalforstas som de omrader, der har fugtindholdca. midt mellem de to yderpunkter. Antalletaf malinger afhaenger af gulvets st0rrelse, setabel 6.

Tabel 6 fugtmalingcr gulv

Gulvst0r-relse im 2

Antal ikke-destruktivemalinger

Antal RFmalinger i

borehuller op til 100 14 2op til 200 27 4op til 400 54 5op til 600 80 6

over 600 14 pr. m 2 1 pr. 100 m 2

Vasr opmaerksom pa, at der ved maling af RF i et borehul skal ga lang tid f0r der er ligevaegt mellem betonfugten og den rela-tive luftfugtighed i borehullet, se Appendix:

Fugtmaling, side 75, vedr0rende maling af fugt i beton og letbeton.

Figur 136 Fugtmaling i beton ved maling af denrelative luftfugtighed i borehuller. Bema;rk atfugtindholdet i betonunderlaget udjsev-nes ved

palaegning af et diffusionstxt lag f .eks. tag-pap . Imaledybden, ca. 0,4 xbetontykkelsen er fugt-indholdet nogenlunde uforandret.

Fugtindholdet i betonunderlag skal vasremindre end 65 % RF, hvis traegulve skallasgges direkte pa betonen.

Hvis der limes en asfaltpap pa betonensom fugtspaerre, skal fugtindholdet i beto-nen vaere mindre end 85 % RF af hensyn tillimens hasrdningsmulighed.

78 F UGTMALING

Fugtmaler

Borehul

lietnifig 0,4xBeton- /,tykrketeen (B

TcEt belasgning

Borehul Borehul-

% RF%RF



Modtagekontrol Nar trasmaterialer modtages pa en bygge- plads, b0r der foretages en modtagekontrol,som omfatter synlige mekaniske skader,styktal, dimensioner, traekvalitet mv.

For trasmaterialer, f.eks. braedder og str0-er, skal ogsa trafugtigheden, der er en

skjult kvalitet, vurderes. Der b0r stilles kravtil trasfugtigheden, f.eks. h0jst 12 %middelfugtindhold, hvilket vil vaere et rea-listisk krav til bl.a. gulvstr0er. Er trasfugtig-heden ikke i overensstemmelse med detStillede krav, kan der senere opsta vanske-ligheder.

Fugtindholdet kontrolleres ved, at der udtages en stikpr0ve. Det b0r pa forhandfastlaegges, hvordan stikpr0ver skal udtages,hvor mange pr0ver der skal udtages,hvordan der skal males, og hvordan male-resultaterne skal behandles/vurderes.

Antallet af stikpr0ver, der skal indga i enmodtagekontrol, er afhasngigt af det an-tal

braedder, str0er eller parketstave, der indgar i opgaven, og af den valgte kvalitets-klasse.

I tabel 7 er der opstillet et forslag til detantal stikpr0ver, som er tilstraekkeligt vedmindre opgaver.

Tabel 7 Forslag til stikpr0veantal ved mindregulvopgaver Styktal/antalm2 i opgave

Stikpr0veantal

Kunstigt t0rrede brsed der/s tave

Naturli gt t0r redeemner

2-89-15

2 3 2 3

16-2526-50

4 5 4 5

51-9091-150 t

s >

o o

9 13

151-280281-500

1827

2032

501-999over 1000

3648

4560

If0lge EDG-Recommendation af22. okto-ber 1994 specificeres der tre fugtklasser for tramaterialer: Standard, Kvalitetst0rret og

Eksklusiv. For hver klasse er der tolerancer for de afvigelser, der ma vasre fra det 0n-skede fugtindhold (malvasrdien). For stan-dard er afvigelserne ± 0,3 x malvasrdien, ogfor kvalitetst0rret er afvigelserne ± 0 2 xmalvasrdien.

For kunstigt t0rrede brasdder og stave kanet symmetrisk interval, f.eks. 8 ± 2 %,omkring det 0nskede mal vasre relevant. For str0er og bjaslker vil der derimod nor-maltkun vaere interesse for den 0vre grasn-se.Der kan f.eks. stilles krav om, at h0jst 5 %af maleresultateme overskrider en fastlagt0vre graense. For stikpr0ver med megetsma antal malinger kan der alter-nativtstilles krav om antal stikpr0ver, h0je-stemiddelfugtindhold, u targ, og antal malinger,som ma overskride u targ + 2 eller 3 pro-cent.

Ved st0rre opgaver kan det vasre af betyd-ning at danne sig et synligt billede af ma-lingerne, variationsbredden og den skasvefordeling, der altid vil va;re for trasfugtind-hold i et parti kunstigt t0rret Xx'<£.

Dette gaslder isaer for traematerialer fra etsavvasrk, medens f.eks. parketbrasdder og

pladematerialer ofte har en meget konstantmiddelfugtighed med en meget lille varia-tionsbredde omkring middeltallet.

M ODTAGEKONTROL

Eksempel 1:Der kraeves ti stikpr0ver med et middelfugtind-hold pa h0jst 12 %. Desuden ma h0jst en ud af ti malinger vsere st0rre end eller lig med 14%.Hvis en maling er 14% eller derover, skal der foretages yderligere ti malinger, og ingen af disse ma VEere 14 % eller derover.

De ti malinger skal altsa bade have et middel-fugtindhold pa h0jst 12 % og opfylde kravetom at v»re rnindre end 14 %.



Der er taget udgangspunkt i kravet Stan-dard, og stillet krav om at 95 % af resulta-terne skal ligge under 12 + 0,3 x 12 dvs.under 15,6 %, idet der kun er ensidige kravtil afvigelsen (krav til h0jeste fugtindhold).Dette krav er klart opfyldt, idet kun enmaling, svarende til 2 %, ligger uden for intervallet.

Er kravet Kvalitetst0rret skal 95 % af malingerne ligge under 12 + 0,2 x 12, dvs.under 14,4 %. Der ligger fire malinger svarende til 8 % over den 0vre graense. Meddette kvalitetskrav ma partiet altsa for-kastes.

PlanhedPlanhedsmaling af gulve og underlag er kort omtalt her. For yderligere oplysninger henyises til GSO Gulvfakta, der mere detal-

jeret beskriver fremgangsmaden ved maling. Bemcerk at det er vigtigt bade at vaere

enige om, hvilke krav der skal opfyldes, oghvordan der skal males. Henvises der tilforskellige metoder, vil krav og maleresul-tater ikke kunne sammenlignes.

Kravene til gulve er som regel, at de skalvasre plane og vandrette. Ved planhed for-stas, at alle gulvets punkter ligger i samme

plan, som kan vasre vandret eller have enhffildning. Afvigelser konstateres som lun-ker eller forh0jninger. At gulvet er vandret

betyder, at alle punkter bade er i samme plan, og at planet ligger vandret. Afvigelser konstateres som hasldning af gulvet.

Normalt regnes der ved planhed med ± 2mm pa et 2 m retholt (og ± 0,6 mm pa et250 mm retholt), se figur 137.

Kravene til planhed gaslder ikke kungulvoverfladen men for mange trtegulveogsa underlaget, dvs. oversiden af str0lagetfor basrende gulve og undergulvet for de0vrige typer.

Tabel 8 Registering af fugtmaling. Bemsrk denasymmetriske fugtkurve.

Traefugt

% Antal Akkumuleretantal %

789

10linniiiiiiim

5 10 515

1030

1112

IIIIIIIIIIIIimiiiii

12 9 2736

5472

1314

linnmi

64

4246

8492

1516

ini

3i

4950

98100

1718

Figur 1 37 Maling at planhed med et retholt pahenholdsvis 250 mm og 2000 mm.

80 MODTAGEKONTROL

Eksempel 2:I et parti pa 500 fyrreplanker til str0er pi 50x100 mm krasves, at fugtindholdet h0jst mavsere 12%. Stikpr0vest0rrelsen er 50. Det er aftalt, at der males med modstandsmaler medisolerede elektroder i en dybde pa 1/3 af tykkel-sen pa bredsiden pa midten af plankernes l;sng-de. Der males kun et sted pa hver planke.

De enkelte maleresultater indf0res og behand-les som vist i tabel 8.

0,25 m0,6 mm

Luhke

Lunke0,6 mm

Forh0jning

Forhoining



Mdleudstyr og mating Der anvendes retholter pa henholdsvis 2 mmed 2 mm h0je ben og 0,25 m med 0,6 mmh0je ben.

Ved kontrol af planhed anvendes f0rstden side af retholtet, som ikke har ben. Ret-holtet skubbes hen over gulvet for konstate-ring af eventuelle ujaevnheder. Kontrollenforetages jeevnt fordelt over gulvet, mendog med en overvsegt langs vtegge og forand0re og vinduer. Hvis der ved den indleden-de kontrol konstateres ujaevnheder, vendesretholtet, sa det hviler pa benene. Uanset

placeringen ma der ikke vasre mere endhenholdsvis 4 mm og 1,2 mm afstand mel-lem gulvet og underkant af 2 m og 0,25 mretholt. Retholtet skal endvidere hele tidenhvile pa begge ben, ellers er tolerancekra-vene overskredet.

Afstanden mellem gulv og retholt kon-trolleres mest bekvemt med en maleklodsmed den dobbelte tykkelse af det anvendtetolerancekrav, f.eks. en 4 mm klods til atmale tolerancer pa ± 2 mm, og en 1,2 mmklods til tolerancer pa ± 0,6 mm.

EftergivelighedTrsegulve ma gerne vasre elastiske og fjed-rende, men ma ikke vaere sa eftergivelige atdet resulterer i generende nedb0jninger eller rystelser, f.eks. i form af at m0bler vipper og porcelaen klirrer i skabene, vedgang pa gulvet.

En forudsaetning for at fa et stabilt gulv er at alle underst0tninger for str0er fungerer korrekt. Underst0tningerne skal vaere solideog skal kunne fikseres i forhold til str0en,som skal hvile pa alle underst0tninger. Joh0jere underst0tning jo mere stiv/uelastisk

b0r den vaere for at reducere deformationer-ne ved trafik pa gulvet. Ved meget h0jeunderst0tninger - dvs. over 100 mm -anbefales det at anvende uelastiske materia-ler som mursten eller beton til den nederstedel af underst0tningen, i stedet for mereelastiske materialer som f.eks. plast. Bl0de

brikker udf0res med dimensioner og af materialer som specificeret pa side 13.

For str0gulve, som er dimensioneret ihenhold til tabel 4 og 5, ma der forventesnedb0jninger pa op til 2 mm ved gang pagulvet. Nedb0jningen males enten i midtenaf et str0fag i forhold til de 2 str0er somafgraenser faget, eller for nedb0jning af enstr0 midt mellem opklodsningerne, se figur 138.

Mellem str0er eller opklodsningcr >

Figur 138 For str0gulve ma der forventes nedb0j-ninger pa op til 2 mm mellem str0er og opklods-ninger.

PLANHED 81

Nedb0jning op til 2 mm



KRAVTil TR/FHIII UP

Bygningsreglementet, BR 95, har kun f0l-gende krav til tragulve:

FlugtvejeGulvbelasgninger i flugtveje, forsamlingslo-kaler og butikker over 150 m 2 skal vasre

brandmaessigt egnede, klasse G gulvbelaeg-ninger, hvilket f.eks. kan opnas med mindst21 mm sammenpl0jede bradder, eller

belasgning af trae i brandteknisk fast forbin-delse med ubrasndbart underlag.

Anvendes der belasgninger af toe i min-dre tykkelse end 21 mm uden brandteknisk fast forbindelse med ubrasndbart underlagskal belaegningen afpr0ves efter NT 007/DS1063.2. Se endvidere TJUE 38, Tra: og brand.

Ildsteder Gulvet skal vaere af ubrandbart materialeeller vsre fast beklaedt med ubrasndbartmateriale indtil 300 mm foran lukkede ild-steder, 500 mm foran abne ildsteder. Mate-rialet skal desuden ga mindst 150 mm ud tilhver side for ildstedets abnine.

SkorsteneGulvbelaegninger af tra;, hvis tykkelse ikkeoverstiger 30 mm, kan f0res umiddelbart optil den udvendige side af murede skorstens-vanger (mindst 228 mm tykke eller tilsva-rende f.eks. ved foring) og 50 mm fra stal-skorstene.

Fugtisolering Der er kun generelle bema;rkninger. Derud-over henvises til SBI-anvisning 178, Byg-ningers fugtisolering.

Lydisolering Der er krav til lydisolering for etageadskil-lelser, og derfor kan der indirekte blive stil-let krav til gulvets trinlyddasmpning mv.

82 KRAV TIL TR/EGULVE



T ERMINOLOGI

Brcedder Handelsbetegnelse for savskarne emner der

er mindst 16 mm i tykkelsen og 75 mm i bredden, svarende til mindst 12 x 68 mm for rettede og h0vlede emner.

DilatationsfugeFuge beregnet til at optage bevaegelser i

bygningsdele og -komponenter, f.eks. gulve.

DispersionslimEn lim hvor t0rstoffet er jaevnt fordelt iopl0sningsmidlet. Til brug ved gulve er t0r-stoffet ofte acryl eller PVAc og opl0snings-midlet vand.

Elastisk lag Et lag som i sv0mmende gulve anvendesmellem gulvfladen og det basrende under-lag for at opna de 0nskede lydmaessige oggangmasssige egenskaber.

EPDM En speciel gummitype (Ethylen PropylenDien Monomer).

Flyvest0d Flyvest0d er samlinger, som ikke er under-st0ttede, f.eks. endest0d mellem brasdder iet trsegulv.

Forl0beForl0be betyder at et traestykke eller en

bygningsdel fortsastter uden afhrydelse gen-nem en abning, f.eks. gulvbrasdder gennemen d0rabning.

Grat Langstrakt lokal forh0jning pa overfladen,se figur 39.

HDF High Density Fibreboard er en homogen

trasplade af fine sammenlimede trarfibre,der ved produktionen er komprimeretendnu staerkere end MDF plader. Densite-ten af HDF plader er ca. 870-1070 kg/m3.

IsolationsfugeFuge mellem gulv og tilst0dende bygnings-dele. Fugen skal hindre skader, der kunneopsta ved kontakt mellem traegulvet og detilst0dende va?gge, s0jler etc. pa grund af fugtudvidelser.

KalibrereKalibrering af maleinstrumenter skal fore-

tages for at vaere sikker pa, at malingerne er korrekte. Principielt sker kalibrering ved atsammenligne maleinstrumentet med etinstrument, som er mere preecist. Ofte kanmaleinstrumentet blot justeres, sa det viser korrekt, ellers ma der laves en tabel eller kurve, der viser hvordan, maleresultatet kanoverf0res til den korrekte vasrdi.

Laskning Samling mellem traestykker der foretagesved at sla et ekstra stykke materiale pasiden af de to traestykker, der skal samles.

Lastfordelende pladeltrykfordelende lag Et lag som i sv0mmende gulve optager lasten og fordeler den ud over et st0rreomrade pa underliggende lag, f.eks. enspanplade som fordeler lasten ud over etunderliggende isoleringslag.

Lokal defekt Enkelte afgraensede ujasvnheder f.eks.spring eller grater, se figur 135. For traagul-ve kan det vasre landingsspring, dvs. afvi-gelse i h0jden mellem to nabobradder.

T ERMINOLOGI



Figur 139 Betegnelser for lokale defekter

LunkeLokal forsEenkning af overfladen.

M D F Medium Density Fibreboard er en homo-gen trasplade af sammenpressede/-limedefine trtefibre. Densiteten af MDF plader er ca. 640-720 kg/m3.

NaddefugeSpeciel fuge af tras eller fugemasse der anvendes for at give braddegulve et udse-ende som et skibsdcek. Oftest er fugen i enkontrastfarve til gulvbraedderne.

Oppinding Opstabling af brasdder eller planker medsma pinde indlagt mellem de enkelte lag, saluften kan cirkulere mellem lagene.

OSBOriented Strand Board er plader, der er opbygget af retningsorienterede traeflager,sa der opnas bedre styrke og dimensionssta-

bilitet.

Planhed Planhed betyder, at alle gulvets punkter ligger i samme plan, som kan vaere vandreteller have en hasldning. Afvigelser konsta-teres som lunker eller forhojninger, se figur 140.

Planker Handelsbetegnelsen for savskarne emner,der maler mindst 50 mm i tykkelsen og100 mm i bredden svarende til mindst 43 x92 mm for rettede og h0vlede emner.Gulvbraedder betegnes ofte gulvplanker.Betegnelsen er dog ofte misvisende, fordi

bradderne ikke har plankemal.

Plansk& ret Et tangentialsnit parallelt med toeets la^ng-deakse. Giver ofte et flammet udseende pa

braeddeflader pga. stammens kegle-form.

PVAc Poly Vinyl Acetat er almindeligt anvendt igulvlime.

Paforing Ved paforing forstas, at der pa et eksiste-rende materiale eller konstruktion pasaetteset stykke materiale for at foretage opret-ning.

Radon Radioaktiv luftart, der findes i jorden, ogsom pa grund af stralingsrisiko skal hin-dres i at komme ind i bygninger.

Retholt Et fuldstaendig retliniet braet eller skinne,som bruges som reference ved maling af overfl adeuj as vnheder.

Regenerere Regenerering af harharpen i et hygrometer eller en termohygrograf sker for at bibehol-de harets lcengdeasndring ved fugtpavirk-ning.

°ShoreAEt udtryk for hvor hardt et materiale (fuge-masse) er malt efter en bestemt maleme-tode. Jo st0rre vaerdi, jo hardere er mate-rialet.

84 T ERMINOLOGI

Grube/pore Grat Lunke Spring

ToleranceFigur 140 Maling af planhed. Afvigelser konstate-res som lunker eller forh0jninger.



Spejlskdret Et radialsnit - vinkelret pa arringene -giver et stribet udseende pa brasddeflader.

Stukning Sammenpresning af fibrene i et stykke tra,som derved far en blivende deformation.

ToleranceTolerance bruges til at definere hvilkegrasnser for afvigelser, der er acceptable.

Normalt anvendes symmetrisk tolerance,dvs. en afvigelse kan vaere enten positiveller negativ, f.eks. ± 2 mm.

Vandrethed Vandrethed betyder at gulvet er plant, og at

planet ligger vandret. Afvigelser konstate-res som hasldning af gulvet, se figur 141.

Figur 141 Afvigelser fra vandrethe d konstatere sved haddning at gulvet.

»Vaskebrcet«Lidt st0rre regelmaessigt gentagne ujasvnhe-der. Ses f.eks. ved fugtskadede traegulve,hvor bradderne krummer pa tvasrs af bred-den pa grand af udvidelse af undersiden, sefigur 142.

Figur 142 Vaskebrxt skyldes tv<erkrumme brsedder

VindskceveVindskasve betyder, at de fire hj0rner i et

brast, en str0 eller en planke ikke ligger isamme plan (typisk pa grand af at der er sket en vridning i traestykket).

LlTTERATUR

Statens Byggeforskningsinstitut:

Malemetoder til bygningsunders0gelser,

Erik Brandt, SBI-anvisning 170, 1990.Bygningers lydisolering - nyere bygnin-ger, J0rgen Kristensen, SBI-anvisning 172,1992.Bygningers lydisolering - asldre bygnin-ger, J0rgen Kristensen, SBI-anvisning 173,1992.Bygningers fugtisolering, Nils Erik Andersen mfl., SBI-anvisning 178, 1993.Konstruktioner i smahuse, J0rgen Munch-Andersenm.fi, SBI-anvisning 189, 1997.Vadrum, Erik Brandt, By og Byg Anvis-ning 200, 2001.

Trabranchens Oplysningsrad:

TR/E 32, Krydsfiner, 1991.TFLE 36, Trarfiberplader, 1993.TR^ 37, Spanplader i byggeriet, 1994.TR^ 38, Tra; og brand, 1995.TRiE 47, Traegulve 2 - Valg og vedlige-holdelse, 2001.TRiE 50, TRyE - Kvalitet og egenska-

ber, 2003

BygErfa-blade:

Fugt i tragulve over kraftigt isoleredeterrsendsek, (13)950224Terrsendask med trasgulve pa str0er og

varmer0r, (13)980924yandskade pa trajgulve, (43)930113Abne fuger i trajgulve, (43)990923Opbuling af trasgulve som f0lge af (bygge)fugt i rumluften, (43)991123

0vrige:

GSO Gulvfakta, Gulvbranchens Samar- bejds- og Oplysningsrad.FSO Fugeguide, Fugebranchens Samar-

bejds- og Oplysningsrad, 2004.

LlTTERATUR

Afvfgelsir fra^arfatet -



S TIKORDSREGISTER

Aflastningsspor, s. 46Afretningslag, s. 16

Afslibning, s. 71Asfaltpap, s. 13

Betondask, s. 16Bjadkeafstande, s. 44Bjaelkelag, s. 16 Bl0de

brikker, s. 13 Braidder,s. 83 Basrende gulve,s. 4 B0jler, s. 21

Dampspasrre, s. 14 Data-logger, s. 76Dilatationsfuge, s. 40, 83Dispersionslim, s. 83

Dykkere, s. 19Eftergivelighed, s. 81 Elastisk lag, s. 83 Elektrisk modstandsmaler, s. 77 EPDM,s. 83

Finerede bradder, s. 10Flugtveje, s. 82Flyvest0d,s. 51,83Forl0be, s. 83 Fugemasse,s. 41 Fugeprofiler, s. 42Fuger, s. 40, 71Fugtisolering, s. 82

Fugtmaling, s. 75Fugtmaling i beton, s. 78Fugtspaerre, s. 14Fuldlimning, s. 20

Grat, s. 83 Gulvbra;dder, s.7 Gulve pa. bjaslkelag, s. 4Gulvopbygning, s. 6Gulvpap, s. 15

Gulvstr0er, s. 11,47Gulvtyper, s. 6

Gulvvarme, s. 31Gulvvarmesystemer, s. 32Gummikork, s. 15

HDF, s.83

Ikke-basrende gulve, s. 4Ildsteder, s. 82Isolationsfuge, s. 40, 83Isoleringsmaterialer, s. 13

Kalibrere, s. 83 Kapacitivfugtmaler, s. 75 Klammer,s. 18 Klik-samlinger, s. 21

Klodser, s. 10 Klodsgulve,s. 68 Knirkende gulve, s.18, 73 Korkgummi, s. 15Korksmuldpap, s. 15Krumme braedder, s. 51Kvaeldning, s. 22

Lamelbraedder, s. 9Laminat brasdder, s. 10Lasknihg, s. 83Lastfordelende plade, s. 83Lim, s. 20Limede gulve, s. 5, 59Limning af asfaltpap, s. 20

Limning i fer og not, s. 20Lokal defekt, s. 83 Lunke,s. 84 Lydisolering, s. 82Lydmajssige forhold, s. 38Lasgning af gulve, s. 43

86 STIKORDSREGISTER



Maskins0m, s. 18MDF, s. 84Melamin brasdder, s. 10Modtagekontrol, s. 79Monta-flex, s. 19Mosaikparket, s. 9, 65Maleudstyr, s. 81 Maling, s.81

Naddefuge, s. 42, 84

Opklodsninger, s. 12, 44Opklodsningsafstande, s. 47Oppinding, s. 84 OSB, s. 84

Parketbraedder, s. 8Parketgulve, s. 64Parketruder, s. 9, 65Partielle reparationer, s. 72Planhed, s. 80, 84 Planker,s. 84 Planskaret, s. 84Plastfolier, s. 14 Plata-Flex,s. 19 Psykrometer, s. 76PVAc, s. 84 Paforing, s. 84

Radon, s. 84Regenerere, s. 84Renovering, s. 70Reparationer, s. 72Retholt, s. 84Revnedannelser, s. 74

Sand, s. 16"Shore A, s. 84Skibsfuger, s. 42Skorstene, s. 82Skruer, s. 17, 19Skumplast, s. 15Spacers, s. 24Spejlskaret, s. 85Spirals0m, s. 18Spunskruer, s. 19Stavparket, s. 8Str0afstande, s. 44Str0er, s. 11Str0gulve, s. 4, 38, 43Stukning, s. 85Svind, s. 22Sv0mmende gulve, s. 4, 39, 54S0m, s. 17, 18S0mmede gulve, s. 5, 59

T-dykkere, s. 17Termohygrograf, s. 76Tolerance, s. 85Trinlydsdasmpende materialer, s. 15Trykfordelende lag, s. 83Tryksvind, s. 74 Tvasrkrumme

braedder, s. 74 10-braetsmal, s. 24

Udvidelsestryk, s. 74Underst0tningsafstande, s. 43

Vandrethed, s. 85Vaskebrast, s. 85Vindskssve, s. 85Vadrum, s. 36

STIKORDSREGISTER



Bogen er udarbejdet at Statens Byggeforskningsinstitut ogTraebranchens Oplysningsrad i samarbejde med:

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Manuskript: Seniorforsker civilingeni0r Erik Brandt,By og Byg, Statens Byggeforskningsinstitut

Redaktion: Trasbranchens OplysningsradGrafisk tilrettela?gning: Trine Preisler

Tegninger: Peter Nielsen Koncept & IllustrationFotografi: Per Jacobsen Fotografi og Digital Studio

Tryk: G0tze Grafisk, Herning

Copyright © 2004: Trasbranchens Oplysningsrad3. udgave, 1. oplag, juni 2004

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