Chapter 2 Flashcards
1
Q
Functions of Finish Ceiling
A
- Controls diffusion of light and sound
- Prevents passage of sound vertically
- Control combustibility and passage of fire
- Part of distribution system for HVAC and lighting
- Accommodate sprinkler heads and loudspeakers
- Play a part in the visual expression of the room
- Ceilings can take variety of shapes and finishes to achieve its objectives including, flat, slope coffered, or vaulted
2
Q
Exposed Structural and Mechanical Components
A
In many instances exposing the structural and mechanical components is appropriate
- Where appearance is not as important e.g. industrial or agricultural buildings
- Where structure is inherently attractive such as heavy timber construction or architectural concrete and steel
- Where exposed services add aesthetic appeal such as in restaurants
- Care and planning is required when systems are to be left exposed and it may increase cost
3
Q
Tightly attached Ceiling
A
- Ceilings of different materials may be tightly attached to the underlying structural elements
- Special finishing arrangements need to be worked out for vertically projecting structural members such as beams
- Special consideration needs to be given for ducts, conduits, pipes and sprinkler heads that are below the ceiling
4
Q
Suspended Ceiling
A
- Ceiling that is suspended on wires
It can conceal structure and services in space above called plenum - Ceiling can be flat even though the structure may be sloped
- Ceiling can serve as membrane fire protection for floor or roof structure above
- Can be made from variety of materials
5
Q
Suspended Gyp and Plaster Ceiling
A
- Can be framed onto light gauge steel cee channels
- More complex shapes can be created with special framing members and by lathing e.g. auditoriums, theatres, and lobbies of public buildings
6
Q
Suspended Acoustical Ceilings
A
- Made from fibrous materials in form of ties or panels referred to as acoustical ceilings because it is absorptive to sound
- Most economical type consists of lay-in-panels supported on exposed grid. Concealed grid is possible but require special panels
- most common in commercial construction
7
Q
Noise Reduction Coefficient (NRC)
A
- Sound absorption is measured as Noise Reduction Coefficient (NRC). Higher the value better its absorption but more transmission and therefore needs sound proofing
8
Q
Ceiling Attentuation Class (CAC)
A
Ceiling Attenuation Class (CAC) is the ceilings ability to reduce transmission through plenum
9
Q
Articulation Class
A
Articulation Class is a measure of sound reflection and absorption related to speech clarity
10
Q
Suspended Fire Resistance Rated Ceilings
A
- Suspended ceilings that are part of a fire resistance rated floor/ceiling or roof/ceiling assembly may be made of gypsum, plaster or lay-in panels and grid systems designed for that purpose
- Penetrations in such membrane ceilings must be detailed to maintain the FRR
- Lighting fixtures must be backed up with fire-resistive material
- Air conditioning grills must be isolated from the ducts that feed them by fire dampers
- Access panels must meet the requirements
11
Q
Ceilings
A
- form a part of a system that accomodates lighting, partition attachments, supply- and return air grilles and diffusers, speakers, and other construction components
12
Q
Ceiling classification
A
- how they are attached
- suspended
- attached directly
- part of the structure
13
Q
Plenum
A
Space above the ceiling
14
Q
Advantages of Suspended Acoustical Ceilings
A
- low cost
- fast installation
- sound control
- Flexibility
- Adaptability
- Easy Accessibilty to Plenum
15
Q
Common Tile and Grid Sizes
A
- 24x24
- 24x48
- 20x60
