Finishes - Ceilings

8/6/2019 Finishes - Ceilings

1/64

CONSTRUCTION AND

MATERIALS

FINISHES

CEILINGS


2/64

CEILINGS Ceilings can be classified into three

groups based on how they are attached tothe structure.

They can be suspended from thestructure,

Attached directly to the structure,

The structure and the finish ceiling can besame component.


3/64


4/64


5/64

CEILINGS (cont.) Residential construction:

Gypsum wallboard placed directly on the floorjoists or ceiling joists with mechanicalattachment using screws or nails.

Commercial construction:

The ceiling is a wire suspended system

supporting a finished surface of acoustical tilegypsum wallboard, or other decorativematerial.


6/64


7/64

CEILINGS (cont.) Suspended ceiling provides a flat ceiling

surface for partition attachment, lights, andacoustical treatment and allows the spaceabove the ceiling, called the plenum, to beused for mechanical systems, wiring, andother services.


8/64

Suspended Acoustical Ceilings These ceilings are the most common type

for commercial construction. They consist of thin panels of wood fiber,

mineral fiber, or glass fiber set in a supportgrid of metal framing that is suspended bywires from the structure.

The tiles are perforated or fissured invarious ways to absorb sound.


9/64

Suspended Acoustical Ceilings

(cont.)

The advantages of suspended acoustical

ceilings include low cost, fast installation,sound control, flexibility, adaptability tolighting and mechanical services, andeasy accessibility to the plenum.


10/64


(cont.) Acoustical ceiling components:

Acoustical ceiling tiles and the metal supporting gridare available in a variety of sizes and configurations.

The most common type is the lay-in system in which

panels are simply laid on top of an exposed T-shaped grid system (See Figure 2.2(a)).

A variation of this is the tegular system that usespanels with rabbeted edges, as shown in Figure 2.2

(b).

Systems are also available in which the grid iscompletely concealed. Figure 2.2(c).


11/64


12/64


(cont.)

Beveled-edged tiles are better than

square-edged tiles because the slightbevel helps prevent edge chipping andconceals minor misalignments betweentiles.

Whichever system is used, the tile at the

perimeter walls is supported by a ceilingangle.


13/64


(cont.)

Manufacturers offer many types of grid

shapes and sizes. Some of these areshown in Figure 2.3. See catalogs fordimensions.


14/64


15/64


(cont.)

Standard ceiling assemblies:

Suspended acoustical ceilings are installed byattaching hanger wires to the structural flooror roof and using these wires to support

lengths of the grid system spaced 1.20 m. oncenter.

Cross tees are then snapped into prepunched

holes in the main runners every 60 cm.

Figure 2.5.


16/64


17/64


18/64


(cont.)

Because acoustical ceilings cannot stop

sound from passing through them, plenumsound barriers are required abovepartitions that extend from the floor to theunderside of the suspended ceiling whenacoustical privacy is needed.


19/64


(cont.)

The easiest and least expensive way is to

lay fire-rated sound attenuation insulationon top of the ceiling tile for a distance ofabout 1.20 m. On either side of thepartition line, as shown in Figure 2.6.


20/64


21/64


22/64


23/64


24/64


25/64


26/64


27/64


28/64


29/64


30/64


31/64


32/64


33/64


34/64


35/64


36/64


37/64


38/64


39/64


40/64


41/64


42/64

Coordination Because ceilings serve so many purposes in

todays construction in addition to acousticalcontrol, there are many elements that must be

coordinated with the selection and detailing of

ceiling system. These elements can include recessed lights,

duct work, sprinkler piping, fire alarm speakers,

smoke detectors, and other recessed items.


43/64

Surface Mounted Items All the mechanical, electrical, and

architectural items that must be mountedon the ceiling should be considered.

They must be located consistent with the

design plan, while satisfying the limitationsand of functions and code requirements.

Light fixtures, HVAC air grilles and

registers, speakers, smoke detectors,sprinkler heads, fire alarms and signs.


44/64


45/64


46/64

Recessed Lights The space above suspended ceiling is

packed with ducts, conduit, and piping. It must be verified that there is sufficient

clearance for recessed lights, andspecified design features.


47/64

Access If there is a great deal of mechanical

equipment, valves, electrical junctionboxes, and other items requiring access, aceiling system must be selected that is

easy to open up and return into placewithout damage.


48/64

Remodeling Work In remodeling work, painting existing

acoustical tiles is sometimes seen aseconomical way to refinish ceilings.

However, painting may destroy theacoustical value of the tiles.

Instead, replacing or cleaning the tiles

should be considered.


49/64

Heavy Loads When partitions extend only to the suspended

ceiling, additional bracing may be required forheavy loads suspended on the partition, such asbookcases.

Additional bracing will prevent wall shake from

heavy doors being closed and can be used forearthquake bracing.

Bracing may consist of diagonal studs screwed

through the ceiling into the top runner of thepartition and secured to the structural floorabove.


50/64


51/64


52/64

Gypsum Wallboard Ceilings When wallboard is attached directly to

structural framing, such as joists, the onlyother components to the assembly arefasteners tape, and joint compound.

Screws are almost always used for bothceiling and partition construction because

they are faster and easier to install and donot pull out of the framing.


53/64


54/64

G W llb d C ili ( )


55/64

Gypsum Wallboard Ceilings (cont.)

For residential construction, wallboard is

screwed directly to the ceiling joists. Although gypsum wallboard ceilings in

commercial construction provide a

smooth, uninterrupted finished ceiling,they lack the easy accessibility of

suspended acoustical ceilings.


56/64

G W llb d C ili ( t )


57/64


Because of this, where access to valves,

junction boxes, fire dampers, or otherequipment or services is required, accesspanels must be installed in the ceiling.

These are prefabricated steel units with ahinged door that allow the wallboard to be

framed into them.



58/64


In addition to a flat ceiling, gypsum

wallboard can be formed into nearly anyconfiguration.

Stepped, sloped, coffered, vaulted, and

arched ceilings are all possible usingvarious combinations of suspended

framing and studs to form the basic shape.



59/64


When acoustical control is required in

residential construction, resilient channelsare attached to the joists and soundattenuation insulation placed between

joists. For sloped, vaulted, or arched ceilings, itmust be verified that there is no

interference from duct work, piping, orother obstructions.


60/64

Plaster Ceilings Lath and plaster ceilings are constructed

similarly to lath and plaster partitions. Like their partition counterparts, lath and

plaster ceilings cost more than gypsum

wallboard ceilings and are more difficult toconstruct.

However they can easily be curved to formcomplex shapes.

Decorative Suspended Ceilings


61/64

Decorative Suspended Ceilings

Many other types of decorative suspended

ceilings are available. They are all suspended with either wiresor threaded rods anchored to the structure

above. The visible, finished portion of the ceiling

can be vertical metal baffles, wood strips,

mirrored panels, open grids of aluminumor wood, or other proprietary systems.

Integrated Ceilings


62/64

Integrated Ceilings

Integrated ceilings are suspended ceiling

systems specifically designed toaccommodate acoustical ceiling tile, lightfixtures, supply and return air grilles, fire

sprinklers, and partition attachment in aconsistent, unified way.


63/64


64/64

Documents

Finishes - Ceilings