SOUND-DEADENING BOARD
Helps Significantly Reduce Noise Pollution
CLICK HERE for FIGURE A - STC 49 steel studs 24" O.C., test results
CLICK HERE for FIGURE B - STC 39 2" x 4" studs 16" O.C., test results
CLICK HERE for FIGURE C - STC 56 2" x 4" studs staggered 24" O.C., test results
The aim of sound-deadening is to reduce distracting
or irritating noise, rather than “soundproofing” to totally
eliminate sound.
Economically preventing noise transmission through an interior wall was
not an easy problem to solve. Thick walls of dense materials can stop
sound, but, at a high cost and with structural problems created by unusually
heavy walls.
However, sound-deadening materials and techniques are available now to
builders who want to offer this significant benefit to noise pollution-conscious
buyers.
What is Sound-Deadening Board?
Sound-deadening board is a specially made fiberboard product designed
for use in wall systems where sound control between rooms is desired.
It is usually identified with the words “sound-deadening board”
on each sheet or package to distinguish it from other fiberboard products.
Take the “Party” Out of Party Walls
Lightweight panels of sound-deadening board are specially made to trap
noise passing through walls from room-to-room. The 1/2"-thick, 4'
x 8' panels work on the principle of combining dissimilar materials so
that each accomplishes a different acoustical objective. Sound-deadening
board is designed for use under gypsum wallboard. The heavy wallboard
provides mass which retards the passage of sound, while the lightweight
sound-deadening board panels act as an absorptive material which traps
noise.
Tests at nationally known acoustical laboratories have shown that when
sound-deadening board is combined with gypsum wallboard, the resulting
wall is acoustically superior to walls made with
• two layers of sound-deadening insulation board alone
• two layers of gypsum wallboard alone
On-Site Practices
It should be understood that the Sound Transmission Class (STC) values
obtained in actual practice will depend upon many construction factors
in addition to the design of the partition itself. Attention must be paid
to workmanship and construction details, and to acoustical characteristics
of the adjacent floor, wall, and ceiling structures which can provide
“flanking paths” for sound transmission around a given partition.
To be most effective, the perimeters of the walls must be sealed to avoid
sound leaks.
| SOUND TRANSMISSION CLASS (STC) Sound Transmission Class (STC) is widely used as a performance criteria. STC provides a single number which combines the wide range of frequency data points. Many new types of lightweight walls have low values in the middle frequency range as compared to the old solid masonry wall. STC numbers have been adopted by acoustical engineers as a measure of the resistance of a building element, such as a wall, to the passage of sound. The higher the number, the better the sound barrier. How do conventional walls using 2" x 4" stud framing rate by STC? Based upon tests, a typical based wall of gypsum wallboard, using 2" x 3" or 2" x 4" studs, will have an STC of only 38. The following examples show the approximate effectiveness of walls with varying STC numbers. 30 - Loud speech can be understood fairly well 35 - Loud speech can be audible but is not intelligible 42 - Loud speech is audible as a murmur 45 - Some loud speech is barely audible 48 - Must strain to hear loud speech 50 - Loud speech is not audible |