This strong, durable board can be used in many applications where
sound deadening is desired. Recommended for interior applications,
this board is ideal for cutting sound transmission between interior
rooms, between floors, or isolation from outdoor sound.
The aim of sound conditioning is reduction of distracting or irritating
noise rather than "sound proofing" to totally eliminate
Both the building materials and necessary techniques for increased
privacy are available now to the builder who wishes to offer this
significant tenant benefit to noise pollution conscious buyers.
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.
What is . . . Sound Deadening Board?
Sound Deadening Board is a specially made non-structural 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 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'x8' product works on the principle of combining dissimilar materials
so that each does a different acoustical job. 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 acoustically as an absorptive
material which traps noise.
Tests at a nationally known acoustical laboratory have shown that
when Sound Deadening Board is combined with gypsum wallboard,
the resulting wall is acoustically appreciably superior to walls
Two layers of Sound Deadening Insulation Board alone
Two layers of gypsum wallboard alone
Sound Transmisison Class STC
Sound Transmission Class (STC) is widely used as a performance
criteria. STC provides a single number combining the wide range
of frequency data points. Many of the new types of lightweight
walls have low values in the middle frequency range as compared
to the old solid masonry walls.
How do conventional walls using 2"x4" stud framing rate
by STC? Based upon tests, a typical based wall of gypsum wallboard,
using 2"x3" or 2"x4" studs will have an STC
of only 38. However, sound deadening board combined with Gypsum
Wallboard will have an STC of 49!
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. The following examples show the approximate
effectiveness of walls with varying STC numbers.
audible but not
audible as a
loud speech - barely audible
strain to hear loud speech
speech not audible
Variations can be adapted from these basic wall systems:
It should be understood that the STC values obtained in actual practice
will depend on many other construction factors besides the design of
the partition itself. Attention must be paid to workmanship and construction
details, and to the 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.