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Trade
Guidelines and
Information Booklet
A quick reference to best industry practice.
Have your manufacturers recommendations changed?
The information contained in this publication is derived from practical experience and compiled with both education and maintenance reduction in
mind.
It’s intended use is as a guide only to what is considered best practice. With today’s homes becoming more expensive and an industry with diminishing
trade skills, the long term presentation of plasterboard linings is a priority.
Information contained herein is to be taken as a guideline only and does not substitute either manufacturers specifications and/or relevant standards
Alternative Fixing Systems ……………………………………………….1
Stud Adhesive ……………………………………………………………. .2
Substrates ………………………………………………………………….3
External Ceiling Specifications …………………………………………..4
Garage Ceilings …………………………………………………………...5
Intermediate Ceiling Joists & Expansion or Control Joints…………….6
Back Blocking ……………………………………………………………..7 & 8
Loads on Ceilings ……………………………………………………….…9 & 10
Jointing application ……………………………………………………....11 & 12
Australian Standards (New)………………..…………………………...…13
Jointing Tolerances ………………………………………………………..14
Painting Plasterboard …………………………………………………….15, 16, 17 & 18
Pre-paint sign off form …………………………………………………….19 & 20
Levels of Finish ……………………………………………………………21, 22, 23 & 24
Inspection of Level 4 Finish ………………………………………………25 & 26
Lighting………..…………………………………………………………….27
Energy Efficiency …………………………………………………………..28 & 29
Finishing Trades…………………………………………………………….30
Sub Contractor Guidelines …………………………………………………31, 32 & 33
Introduction
Index
Alternative Fixing Method
The 1/3rd fixing method will dramatically improve the long term appearance of plasterboard ceilings
1
2007
Stud Adhesive
Temporary blocks are required on walls, every second stud Remember No pressure—No bond
2
Never underestimate the importance of the role stud adhesive plays in both maintenance reduction and the long term appearance of your internal linings. Rectification is expensive—following the manufacturers’ recommendations is your best insurance. Remember, stud adhesive is one of the cheapest accessories; however, any failures will quickly make it the most expensive.
Manufacturers of stud adhesive have issued many guidelines in the past to assist with the long-term presentation of their products and maintenance reduction. It is important to note that the most bond failures are the result of improper practice and non-adherence to specification.
Achieving Trouble-Free Ceilings
Reduce the trimmers Increase your chance of ceiling failures
3
2007
BATTENED CEILING
In view of the higher wind loadings and other influences on external ceilings, industry has upgraded its specifications for these areas as follows: • 13mm Standard core or 10mm ceiling grade plasterboard is recommended for use in external ceilings. • Framing members should be spaced at max.450mm centres. In areas where ceiling joists or roof trusses are spaced at more than 450mm, trimming or suitable ceiling battens should be provided at max. 450mm centres. Metal ceiling battens and furring channels should be installed in accordance with Rondo specifications. • Run plasterboard sheets at right angels to framing members. Provide a min. 6mm gap between the edges of plasterboard sheet and adjacent walls, beams, columns and fascias. • Ceiling linings should be fully screw fixed at max. 300mm centres, 32mm ‘W’ type screws should be used for fixing into timber framing 25mm ‘S’ or ‘D’ type screws, as appropriate, should be used for fixing into steel framing. • Back-block all joints in ceiling linings as per back-blocking specifications • Control joints should be provided in external ceiling at max. 6m centres in both directions • External ceilings should be painted with three coat exterior paint system applied in accordance with manufacturer’s recommendations. • Roof sarking and cross flow ventilation to the ceiling cavity can improve long term performance of external ceilings by reducing the possibility of condensation on top of the ceiling lining.
External Ceiling Specifications
External ceilings require strict adherence to specification - Non compliance will reflect in the finish—For fibre cement external ceilings
refer to manufacturers specifications for correct fixing details. 4
? Beware the spaced noggings
They don’t work!
The Rules have changed Garage Ceilings—Did you know?
Garage ceilings are the most likely to fail long term.
Cornice will not support sheet ends. Cornice adhesive will not adhere to timber. Cornice bottom member must be firmly fixed, floating bottom
member will bring your ceiling down 5
Plasterboard fixed to underside of trimmers
Plasterboard fixed to underside of framing
Intermediate Ceiling Joists
Expansion or Control Joints
Intermediate ceiling joists - For best results ceilings should be battened
Positioning of control joints should be pre-determined and not left up to the plasterer.
6
Please note: Unrestrained ends of intermediate ceiling joists may cause and warping or twisting, screw popping and reduced adhesive bond.
Back-Blocking
If placing insufficient compound on the back of back blocking or using thin strips and/or undersize back blocking.
Clearly don’t waste your time they don’t work 7
Remember:
Any additional cost in relation to back-blocking mus t be included in your quote. Failure to pro-vide back-blocking installed as per AS/NZS 2589:2007 may render you the plasterer, responsible for any associated costs relating to maintenance and/or rectification caused by jointing defects
Australian/New Zealand Standard AS/NZS 2589.1:2007 Changes to industry construction techniques introduced over recent years have made changes to
the Australian Standards relative to back-blocking necessary, to provide additional support to plasterboard joints.
Back blocking now forms part of plasterboard manufacture specification. It is mandatory fixing practice and forms part of the Australian Standard AS/NZS 2589.1:2007.
Its introduction has been made necessary by changes to industry construction techniques, i.e. complex roof shapes and truss design, with changes in structural direction and lack of proper support for the plasterboard where directional changes occur.
The long term effects of these designs and their impact on plasterboard ceilings are obvious, as is the increasing incidence of maintenance related issues.
Be aware, back-blocking is an additional cost at least in the short term. Experience from other States clearly shows that back-blocking substantially reduces call-backs, in particular cracking and peaking joints. In the long run, back-blocking will produce positive cost benefits.
Manufacturers remain conscious of the need to maintain best fixing practices and presentation of product. Adherence to the new Standards will ensure total warranties and guarantees apply, provided installation is carried out using Manufacturers systems and materials.
Extract from Australian/New Zealand Standard AS/NZS 2589.1:2007
7.7.2.4 Recessed joints in ceilings - All recessed joints on a ceiling shall be back-blocked in any area containing three or more recessed joints.
7.7.3 Back-blocking procedure.
7.7.3.1 Ceiling recessed edge joints - The procedure shall be as follows:
(a) Cut back-blocks at least 200mm wide and long enough to fit loosely between the framing members.
(b) Apply plaster based setting type adhesive cement to back-blocks over the full face of the back-block. A notched spreader to give 6mm x 6mm beads at approximately 20mm centers at right angle to the joint would be satisfactory.
(c) Fix gypsum plasterboard horizontally to framing members. Place back-blocks centrally along the full length of the board edge as shown in Fig.2 (over page).
(d) Immediately after the blocks are in place erect the next board. Ceiling back-blocks may be cemented into position from above the ceiling after the boards have been fixed and before they are flush jointed.
Builders & Plasterers be warned - Recent changes to Australian Standards have
increase your liability!
8
Cut pieces of plasterboard sheet to sizes no less than 200mm wide in lengths that will fit loosely between the framing members
Soak cornice adhesive in a clean container with sufficient water to make a stiff paste of smooth consistency
Fix plasterboard sheets horizontally to framing members, placing the back-blocks centrally along the full length of the sheets edge
Fix the first plasterboard sheet
Apply cornice adhesive to back-blocks and place them between framing members along the full length of the sheet already fixed
Plasterboard ceiling
Plasterboard Sheet
Do not use stud adhesive for back-blocking. Use only back blocking cement/adhesive as recommended. Back blocking strips should not be cut tight between framing members
2007
Loads on Ceilings
9
There are a million things on your mind when building or extending a home. The last thing you need to worry about is whether the plasterboard ceilings are going to cope with the
weight of the ceiling insulation. Using the wrong product could lead to ceilings sagging or possibly collapsing due to excessive weight loading.
Why take this un-necessary risk?
Australia’s leading plasterboard Manufacturers have strict guidelines on the maximum dead load on ceilings. These include:
Boral
CSR
Lafarge
BGC
Not complying with these guidelines can void manufacturers warranty.
Insulation’s range of glasswool ceiling batts can provide the thermal and acoustic requirements you need without weighing down your ceiling.
Glasswool Batts
Loose Fill Cellulose Fibre
“Limit the dead loads on plasterboard ceilings to 2kg/m 2”.
Glasswool
Batts
10
Glasswool & Cellulose Fibre Comparison
Glasswool
Batts
Glasswool
Batts
Tape - Lift, Dry Out
11
Fibre Cement Sheeting
When taping, fill the recess with compound as part of the taping process. If the job is taped with paper tape . Clearly visible with little of no compound
wither under and over the tape -
Specifications have not been met
When taping by hand the recess is filled with compound with the tape being forced in. When using a taping machine a controlled amount of normally over wet compound is applied to the joint via the back of the tape. Surplus compound is then removed with limited pressure. Less pressure means less bond.
12
Australian Standards AS/NZS 2589:2007
13
Did you know? The long awaited Australian/New Zealand Standards for plasterboard fixing and finishing is now complete. Those fortunate enough to have received a copy will appreciate the time and effort spent in the presentation of this document.
The new standards are a major improvement on any past literature and are a must-have for serious contractors.
Contractors should not underestimate the importance of this document to their businesses. Although some may never quite feel the need to get a copy, so many important changes will take a long time to find their way onto the job site, and may result in costly and embarrassing consequences.
As a service to our members, we take this opportunity to highlight a few relevant points; however, for a more comprehensive insight into the many changes and inclusions that may affect your business, you will be advised through the Association on the availability of the completed document.
The following information must be taken as only a quick guide for Association members. Detailed information must be referenced from the Australian/NZ Standards or individual manufacturer’s specifications.
Tolerances
RECESS EDGE JOINTS
• Total width for recess joint must no be less than 250mm.
• The joint build should be less than 2mm and not display a ridge or peak at the center.
EXTERNAL ANGLES
• The build-up at the metal angle should not exceed 3mm over the width of the joint.
INTERNAL CORNERS
• Joint build should not be less than 2mm.
• Width of joint width either side of corner should not be less than 75mm.
PERIMETER FIXING
• Fasteners should be installed at 300mm centers at all external and internal angles and around window and door openings.
Ventilation
• Adequate ventilation and condensation control is required for long-term performance of plasterboard lining, in accordance with manufacturers specifications.
Stud Adhesive
• Care should be taken with the selection of adhesive for use on treated timber. Daubs of adhesive should be approximately 25mm in diameter and 15mm high. Walls for 1200mm boards - 4 daubs per stud.
Back Blocking
• Ceiling butt joints must fall centrally between framing members and be back blocked to form a recess.
• Ceilings supported by a suspended system do not require back blocking.
• With Level 5 ceilings, all recess joints shall be back blocked regardless of ceiling support system.
• Back blocks to be cut at least 200mm wide to fit between framing members with a gap at each end not greater than 30mm.
Framing Deviations and Tolerances
LEVEL 4 FINISH
• 4mm over a 1.8 straight edge for 90% of area, remainder 5mm.
LEVEL 5 FINISH
• 3mm over a 1.8 straight edge for 90% of area, remainder 4mm.
CONTROL JOINTS
• Control joints in cornice shall coincide with control joints in ceilings.
TAPES
• Where self-adhesive fiberglass tapes are used, the joints must be back blocked.
CEILINGS
• Trimmers are required for truss roof construction.
• For garages and external ceilings, refer to manufacturer’s specifications.
SCREWS
• Screws used for fixing gypsum linings to softwood ceilings substrates should have a minimum length of 30mm (W Type).
Masonry Application
• Wherever the substrate is more than 25mm out of place, the masonry system shall not be used.
• The masonry system should not be used on walls over 3 meters high unless otherwise specified by the plasterboard manufacturer
• Bonding agents may be required adhesion to porous surfaces.
Inspections
• Artificial lighting can be used by the plasterer to assist with the final presentation. However, lighting cannot be used for the inspection process.
Plaster Joint Tolerance Measuring Device Adjudication on the acceptability of finished plaster surfaces could in most cases be compared to winning the lotto. With so many variables influencing the final outcome it’s no wonder many disputes regarding plaster jointing remain unresolved.
When complaints arise regarding visible joints irrespective of how good the plasterers’ argument sounds, he will receive little credibility when faced with an unhappy owner who steadfastly declares that you could not see a join in his last house. The builder will normally align himself with the owner as he only wants to get paid.
In the past, opinions on what’s good and what’s bad were based purely on perception with the only guidelines being joint widths and number of coats.
Tolerances
Recess edge joints are unacceptable if the joint is over built. That is the build up of the joint exceeds 2mm over the width of the joint.
Finally after many years the now released AUS/NZ Standards nominate specific tolerances for plaster recess joints, butt joints, external angles, internal angles.
Defining specified tolerances plus or minus can now be measured with a device engineered precisely for this purpose. Manufactured in compliance with the Australian Standards and Weights & Measures Dept.
External angles
The build up at the metal angle should not exceed 3mm over the width of the joint.
Internal angles
Joint build up should not be less than 2mm. A joint width either side of the corner should not be less than 755mm
Finally we no longer have to rely on perception. There are now recognized guidelines that can be monitored in the event of any dispute.
14
15
2007
16
Back rolling must be done over a wet surface using the roller to create a texture finish, keeping it wet by continual topping up from a paint tray.
The most important but the least understood part of the painting process, is back rolling, when the spray method is used.
Without back rolling the spray method of painting provides no benefits whatsoever to plasterboard
finishes.
The best practice for plasterboard finishes is to use a paint roller. If spray painting is considered then apply the following information
It appears there is a lack of understanding in the paint industry regarding the necessity to back roll particularly when contrary to specifications most painters insist only on back rolling the last coat???Now while back rolling will greatly assist with the proper presentation of plasterboard the expected results will depend entirely on: -
• Temperature conditions at the time of application (premature drying of the paint)
• The drying rate of the paint and the time lapse between the spray application and the roller application.
• Restricting the amount of paint applied will restrict the texture.
• The porosity of the surface.
An advanced state of drying of the paint will limit the ability to provide the required texture and equalise the surface appearance.
Proper Drying between coats.
The masking up and covering of window and door openings required for the spray application restricts the normal air flow inside the residence and can severely hamper the drying
process. It is important to remember although the paint surface may feel touch dry the jointing compound below the paint surface will in all probability be still holding moisture if the second coat is applied too quick.
Sometimes recommended drying times for paint has to be extended when painting plasterboard particularly during periods of inclement weather when the atmosphere is high in humidity and retards the drying process.
Caution: When the system exceeds the limitations, excess moisture can affect the performance of some plaster compounds.
Application To achieve the best possible presentation of a plasterboard surface the following procedure is recommended;
1. Broom down plasterboard surface to remove excess dust.
2. Apply 1 x coat of good quality acrylic sealer (preferably by roller or back rolled if sprayed) and allow adequate drying and curing time.
3. Inspection of the surface to be carried out and minor imperfections to be filled, sanded and spot primed
4. Painting should not proceed over surface blemishes. Pay particular attention to any imperfections identified before the application of further coats
5. Lightly dust down after sanding
6. Apply 2 x coats of desired paint finish to achieve manufacturers recommended paint film thickness and consistency in sheen level allowing adequate drying time between coats. Back rolling will be required after each coat if applied by the spray method.
Guarantees & Warranties Manufacturers specifications are designed for the best presentation of their products.
It is important that guidelines are followed for best results.
When application is by airless spray for best results back roll all coats.
As recommended by leading paint manufacturers
Back Rolling
17
When all else fails When all else fails When all else fails When all else fails ---- Follow the instructionsFollow the instructionsFollow the instructionsFollow the instructions
Applying paint to plasterboard walls and ceilings is one of the most commonly performed activities in the building process. Yet it gives rise to so many complaints why??
The painting of plasterboard cannot be compared to the painting of any other surface.
A completed plasterboard wall or ceiling is really two entirely different surfaces with expectations on completion they will appear identical.
The paint system is required to cope with: -
• Surface and texture variations in the paper faced plasterboard
• The porosity of plaster jointed compounds
The finished appearance of plasterboard walls and ceilings are highly dependant on the application method, the quality of the paint used, colour and sheen level.
Contrary to popular belief the spray method of painting is not the preferred method for the painting of plasterboard. The now widespread method of spray painting plasterboard has been introduced purely and simply to cater for a need for speed in the building industry but still does not compare to the preferred method of roller application.
Spray painting provides the smoothest finish; however, it cannot deliver a uniform finish over the surface variations of plasterboard linings. The orange peel texture appearance necessary to disguise these subtle differences and can only be achieved by a suitable nap roller.
Painting of Plasterboard
18
To ensure a satisfactory finish these differences in surface characteristics must be addressed.
19
20
Level 5 Finishes
Quality is No Accident
Level 5 Finish
Level 5 finishes do not start with the plasterboard.
Decisions on levels of finish need to be determined prior to commencing the project. Level 5 relates to the whole project, not to someone with unreal expectations complaining about finishes at the end of the job. When the dispute stage is reached, improvements in all probability will not achieve level 5. Although level 5 finishes have been designed with the best intentions, there is still a reliance on other trades conforming to proper practice, recommended paint systems and favourable lighting.
Level 5 Requirements Avoid Where Possible
� A level 5 background � Full height glass
� All paint coats to be rolled � Windows abutting walls
� A three coat paint system must be applied � Glancing light
� All ceilings must be battened
� Ceiling joints to run with the light source
� Wall joints to be fixed horizontally
� Back-blocking to all rooms
21
22
23
*Critical lighting: natural or artificial light projected across a surface at a low incidence angle.
Non-critical lighting: when the light striking the surface is diffuse or at right angels, or both.
+May not be suitable for subsequent decoration to high levels of quality in the future.
See Level 4 or Level 5 for upgrading requirements.
SELECTION OF LEVEL OF FINISH FOR LINING
Level 3
Level 3 shall be used in areas that do not require decoration such s above ceiling level or inside service shafts and the like.
All joints and interior angles shall have tape embedded in joint cement/compound and one separate coat of joint cement /compound applied over all joints and fastener heads. All joint cement/compound shall be finished smooth.
Note: Generally this is achieved by scraping off nibs and ridges and the like, with the edge of a trowel.
Level 4
Level 4 shall be the default level for gypsum linings unless specified otherwise.
Flat or low sheen paints shall be used for this level
All joints and interior angels shall have tape embedded in jointing cement/jointing compound and a minium of two separate coats of jointing cement/jointing compound applied over all joints, angles, fastener heads and accessories. All jointing cement/jointing compound shall be finished evenly and be free of tool marks and ridges in preparation for decoration.
Note: 1. In critical lighting conditions, surface imperfections may still be apparent in a level 4
Surface finish.
2. Where gloss, semi-gloss and deep tone paints are used, surface imperfections will be more evident.
Level 5
Level 5 shall be used where gloss or semi-gloss paints are to be used or where critical lighting conditions occur on flat or low sheen paints.
24
WHAT IS THE FINAL DECORATION?
Finish not important or undecorated.
Wall covering, wallpaper or texture
Level 3 Finish
Critical and non-critical lighting
Level 4 Finish
Paint
Flat/Matt/Satin/Low sheen paint
Semi gloss/gloss paint
Pastel/mid-tones Dark tones
Critical and non-critical lighting
Non-critical lighting Critical lighting
Level 5 Finish
Inspection of Level 4 Surfaces
25
There is no doubt most consumers’ expectations of plasterboard finishes are for an absolute blemish-free finish. There is also no doubt that this view is also shared by the builder, plasterer and painter as exactly what they set out to produce. In reality, all that can be expected is an appearance of flatness—absolute blemish-free surfaces are extremely difficult, if not impossible, to achieve.
When expectations of the finish go beyond what can be realistically achieved, then a Level 5 finish should form part of the specifications.
There are many instant experts when it comes down to inspection and adjudication of plasterboard fin-ishes. Now we all know that to be a referee or a judge in a particular field certain qualifications are in or-der, not with plasterboard it seems. Anyone with a torch to shine up the wall or a 1000w spotlight in their hand
inherits an instant licence to destroy the plasterer or make him suddenly think he may have chosen the wrong trade.
Most building associations have guidelines for the inspection of plaster finishes, the majority of which
seldom receive consideration when it comes down to the dispute resolution process.
• It is recommended that visual inspections on finished surfaces be carried out in normal daylight
conditions.
• No torches, no artificial light, no 1000w halogen spotlights.
• Artificial light to be used only to assist the plasterer in carrying out his work—not for inspection
purposes.
• To avoid glancing light, these inspections should be carried out between the hours of 10am and 2pm.
• The inspection of a particular surface should bel carried out at a distance of 1.5 to 2.0 metres. Where
differences of appearance are not clearly discernable, then that finish is normally considered
acceptable.
The current Australian / New Zealand Standards clearly states
NO ARTIFICAL LIGHTING CAN BE USED FOR IDENTIFICATION OF PLASTER FINISH
DEFECTS.
Many disillusioned home owners normally have a relative that just happens to be (you guessed it) the worlds best plaster.
You may ask: “Why didn’t they do the job?” Too busy? No, Too smart!
Expectations and Inspections of Plasterboard
Surfaces
26
27
Lighting Much has now been said about the effects of lighting on
finished plaster surfaces.
Despite our best efforts with education, literature and illustration, there are still many hurdles to overcome. Particularly when attempting to demonstrate to a less than happy owner (one who has just viewed for the first time the ceilings of his/her new home at night), the circumstances behind this unwanted phenomenon
occurring in their residence.
As industry professionals, we are faced with a constant challenge to give a better understanding to designers and builders—so that they may indicate to the end-user the standard that can reasonably be expected from the choice of materials and design within their nominated budget.
Unfortunately, there is still a gap between the owner’s expectations of plasterboard finishes and what is realistically attainable; particularly when consideration is given to the materials, substrates and systems that are available.
When considering the type of finish required from plasterboard, it is important to understand how the overall appearance is to be affected by glancing light.
We are aware that the common requirement is for a flat blemish-free surface. However, despite everyone’s best
intentions, this is not always possible to achieve.
Today’s contemporary designs pose many problems for plasterers, particularly when these designs include large ceiling areas and window openings. Anyone who has ever built opposite the water canal estates, swimming pools etc. will testify to the dramatic change in appearance that can be caused by light reflections.
It is strongly recommended:
• The installation of low-cost plastic shades over any bare bulb, in order to avoid glancing light on plasterboard ceilings.
• Avoidance of fluorescent tubes, unless they can be installed at right angles to any plastered joints, or recessed into the ceiling.
• Caution is recommended when considering circular fluorescent lighting. (The effect will disappoint).
• Adjustment of any spotlights so as to avoid glancing light on ceiling or walls.
This action will, in all probability make the difference between owner’s acceptance or rejection of the appearance of the ceilings or walls in their new residence, and may avoid the obvious requests for rework to be carried out. However, be aware rework may not provide the total solution.
Creative lighting can be used for effect on plasterboard walls or ceilings.
Downlights in most situations will be favourable. However downlights in passageways toilets wall niches or any areas
close to walls may highlight imperfections and should be avoided.
The installation of cheap lightshades will dramatically reduces the disputes at handover.
Pla
ster
boar
d Jo
int
Pla
ster
boar
d Jo
int
Flu
ores
cent
Lig
hts
Glancing light reflected upwards from pool water to interior walls and ceilings.
Plasterboard
Joint
Plasterboard
Joint
Fluorescent
Lights
28
Energy Efficiency (Environmentally friendly is not necessarily plaster friendly)
With energy efficiency regulations now part of all building programs, it is not all good news for plasterers.
Benefits by way of ventilation whirlybirds, light colour roofs, wider eaves, sisalation etc. are welcome inclusions, not so for the increased use of insulation. Now I know we all recognise the benefits of insulation in the ceiling space however, inexperienced installers will complete their job totally unaware of the damage caused to finished plaster ceilings. Of particular concern is when the insulation installer is closely followed by the installation of ducted air conditioning.
Following all this movement inside the ceiling space, how is it that the plasterer will be held responsible for screw pops and just about everything else classed as maintenance.
Generally it is considered that whatever appears in the plaster finish belongs only to the plasterers.
Surely they can’t be serious
29
Energy Efficiency (Efficiency = Deficiency)
Choice of lighting will greatly influence the appearance of ceilings in new homes. Just when we almost had it right, energy efficiency ratings could deliver a new set of problems.
For many years we have fought hard with builders and unhappy owners regarding the use of light shades, (witches hats, call them what you like) to enhance the appearance of plasterboard ceilings.
The popularity of down lights (although not the total solution) have proven excellent value for the presentation of large ceilings.
Many in the industry are slowly becoming aware of the need to control glancing light on plasterboard finishes, although convincing the uninitiated however has never been easy.
Favourable lighting on ceiling = happy customers, mandatory energy efficient fluorescent globes are non sympathetic to plasterboard ceilings and have the potential to put the industry back 10 years.
The solution is simple.
Energy efficiency globe with no shade.
Energy efficiency globe fitted internally.
Builder
• To ensure all timbers are plumb and true prior to plasterboard application
• To ensure framing noggins are flush with framing studs
• To ensure truss support brackets are flush with truss chords
• To ensure correct amount of trimmers are installed at the change of truss direction and perimeter of
rooms.
Plasterer
• To ensure plasterboard is fixed in accordance with manufacturers’ specification
• To ensure plaster jointing is carried out in accordance with manufacturers’ specifications
• To ensure all plastered joints, screw heads and angels are sanded down and made good prior to
painting
• To ensure a pre-paint inspection is carried out with the builder/supervisor/owner after the first paint
coating is applied (mark up with pencil)
• To ensure all patching of the pre-paint inspection is sanded down and made good prior to subsequent
coats of paint being applied.
Painter
• To ensure correct amount of paint coats and thickness are applied in accordance with manufacturers’ specifications.
• To ensure pre-paint inspection patching is spot sealed prior to subsequent coats being applied
• To ensure minor imperfections are filled, sanded and spot sealed
• To ensure gaps and cracks are closed prior to painting
• To ensure first coat is sanded to remove foreign particles and dusted down prior to finishing coats
being applied.
Electrician
• All wires must be permanently positioned prior to the installation of plasterboard
• Plasterboard should not support electrical fittings, lights etc
Insulation
• Observe load limit regulations on plasterboard ceilings
• Wall - do not force insulation between studs
Finishing Trades Roles & Responsibilities
30
Sub-Contractor Guidelines
31
Fixing-Walls
Settings
� Internal angles to be used where specified.
� Use ring shank nails for plasterboard into pine framing.
� All boards to be lifted 10mm from the floor
� Power point holes to be positioned in the centre of the bracket.
� Villaboard to be nailed at 150 to 200mm behind tile areas.
� Metal plasterers’ angles to be installed in wet areas.
� Temporary blocks to be used where practical (Maximum: every 3rd stud).
� No joints to appear over a window or door stud.
� No folding of sheets allowed (unless only used to straighten walls, and angles are rein-forced with paper tape).
� Nailing around door and window opening to be 300mm centres. (Do no rely on architraves to hold board edges).
� Nailing for internal and external angles to be 300mm centres.
� Penetrations in walls to be cut neatly. Do not use hammer or other impact tools.
� Paper tape only to be used for joint reinforcements.
� No additives or retarders to be used.
� Joints to be set 280mm wide using a three coat system. (First and second coats to be plaster base for a stronger joint).
� Setting beads to be used on all offset angles (flex tape to difficult profiles).
� Minimal build-up on external angles and feathered out along skirting line.
� Joints and nail holes to receive three coats with zero build-up.
� Nails around openings to be set prior to the fixing of architraves.
� Pinholes in top coat to be patched.
� Compound dry-out can occur on hot or windy conditions - i.e. the compound dries quicker than the setting action of the plaster.
� For mechanical application ensure sufficient compound is applied as part of the taping process. Lack of compound below the tape will cause dry-out or bubbles in the tape.
32
Stud Adhesive
Fixing - Ceilings
� Avoid delayed contact with stud adhesive, particularly on windy days.
� Walls - 4 daubs per stud for 1200mm or 1350mm width board.
� Daubs of adhesive to be 25mm diameter / 15mm height.
� No stud adhesive to be used behind tiled areas. (Nail or screw at recommended spacing).
� Stud adhesive should be left to cure at least 24 hours prior to commencement of jointing; 48 hours in wet conditions.
� Do not use stud adhesive for back blocking.
� Temporary blocks should be used on walls every second stud. (Maximum: every 3rd stud).
� Ceilings may need temporary blocks during wet weather.
� All light wire to be pulled through.
� Manhole covers to be cut out and left visible.
� Back blocking as per Australian Standards (any room with three or more joints).
� Butt joints to fall between trusses and be back blocked.
� Ceiling boards to be supported on ends where fixing is not provided by builder.
� No screws to be driven though stud adhesive.
� Butt joints to be staggered and back blocked between framing members.
� Fixing points 240mm centres maximum - adhesive / screw.
� No stud adhesive to be used for back blocking.
33
Cornice
� No retarders to be used.
� Remove all temporary nails at time of installation.
� All mitres to be buttered as per manufacturer’s specification.
� All members to be clean and nay damage to be repaired.
� Mechanical fixing is required around cupboard and where fixed to timber beams etc.
� All mitres to be cut tight.
� All mitres to be left clean and sharp.
� When bonding cornice to villaboard, reduce porosity by dampening areas or bonding agent to dry out.
� Cornice bottom member must be firmly fixed to brickwork.
� A continuous bead of cornice adhesive (10mm x 10mm) is required on top and bottom members.
A dozen good reasons why you should join the Walls & Ceilings Association
• Advice on securing payment for your work.
• Getting it right for OH & S regulations
• Licensing issues
• Up Skilling you workers
• Promoting drywall installations
• Technical advice
• Industry News Updates
• Technical Support
• Dispute Resolution Assistance
• RTO endorsed Passive Fire Training
• Contributing to policy making regarding the Australian Standards
& Building Codes
• National Magazine
AWCI Working for You
State Branches
AWCI Queensland
PO Box 3896, South Brisbane
QLD 4101
P: 07 3846 5688
F: 07 3844 9828.
AWCI Victoria
Suite 4/41 Glenhuntly Rd, Elwood VIC 3184
P: 03 9531 4703
F: 03 9531 1120
AWCI New South Wales
PO Box 6142, Parramatta
NSW 2150
P: 02 9891 6188
F: 02 9891 6452
AWCI Western Australia
PO Box 4056, Victoria Park
WA 6879
P: 08 9362 5977
F: 08 9470 2870
AWCI Tasmania
734 Nugent Rd, Wattle Hill
TAS 7172
P: 03 6272 1411
F: 03 6273 0880
AWCI South Australia
12-22 Richmond Road, Keswick SA 5035
P: 08 8371 5499
F: 08 8292 4040
AWCI New Zealand
PO Box 302-486, North Harbour Auckland 0751 NZ
P: 0011 64 9 440 9469
F: 0011 64 9 414 4593
