Deck 32: Acoustical Materials

Question 1

What is acoustical plaster?

Answer 1

Acoustical plaster is composed of a plaster made with perlite or vermiculite aggregate. It may be applied with a brush but is usually sprayed on surfaces. It has the advantage of uniformly covering curved and irregular shapes. The plaster is applied in several layers, with a finished thickness of about 1/2 in. (12 mm). It has an NRC of about 0.21 to 0.75.

Question 2

​Explain what baffles are and identify two types.

Answer 2

Baffles are acoustical panels hung from a ceiling to reduce airborne sound in large spaces, such as factories, restaurants, or auditoriums. Vinyl-covered fiberglass baffles use lightweight panels available 1 in. (25 mm) thick, 10 in. (254 mm) high, and from 2 to 4 ft. (610 to 1220 mm) long. Flame-resistant polyethylene is bonded over a 1 in. (38 mm) fiberglass core. It is flexible, like a blanket, and hung from a ceiling. Another type of baffle uses rigid wood-fiber sound-deadening panels. These baffles can be joined to form an attractive grid on a ceiling. ​

Question 3

____ is available as thin as 0.0005 in. and is used in walls, doors, and other areas where a thin but effective sound barrier is needed.

A) Lead
B) Concrete block
C) Acoustical sealant
D) Gypsum

Answer 3

A

Question 4

Building codes typically require that floor-ceiling assemblies have an impact isolation class rating of ____.

A) 20
B) 50
C) 90
D) 120

Question 5

What is acoustics and how are acoustical materials used?

Question 6

____ dB is the level at which a feeling of vibration in the ear can be produced.

A) 80
B) 100
C) 120
D) 140

Question 7

What materials can be used to dampen sound from mechanical equipment?

Question 8

Sound waves travel at a speed of approximately ____ ft/sec through the air at sea level.

A) 445
B) 900
C) 1130
D) 1270

Question 9

What are the typical building code STC requirements for residences, apartments, and hotels?

Question 10

What type of ceiling tile material is fire resistant and used in areas of high humidity?

A) Sugarcane fiber
B) Ceramic
C) Wood
D) Aluminum