Arlington, Va.—If silence is truly golden,
then a new study co-sponsored by the Carpet Cushion Council (CCC) and the
Alliance for Flexible Polyurethane Foam (AFPF) will be music to the ears of
flooring contractors whose clients are eager to enhance productivity by assuring
a quieter environment. According to just-released test results, the use of
properly specified separate commercial carpet cushion significantly enhances
broadloom’s well-known ability to absorb sound. In a recently completed
acoustics study, carpet installed with commercial cushion demonstrated as much
as double the sound absorption compared to broadloom alone.
The groundbreaking new acoustical research,
jointly sponsored by CCC and AFPF, and conducted by Intertek Testing Services
(ITS), measured the sound-absorbing capacity of cushion under carpet. “Carpet
directly glued down without cushion absorbs less than half as much noise as when
a proper cushion is installed under it,” said Bill Wald, CCC’s technical
director. “Using a cushion under broadloom in commercial installations should
become standard practice, just as it is in residential installations. Today,
there are broadloom cushions available that are specifically designed for use in
commercial applications.” The Noise Reduction Coefficient (NRC) is a measure
of the effectiveness of a material in absorbing sound over several frequencies.
The results of the new research showed that
carpet alone, glued directly to a concrete substrate, Wald noted, has an NRC of
approximately .25 (1.0 represents 100% sound absorption), which means it absorbs
about 25% of the sound directed at it. When a commercial bonded polyurethane
broadloom cushion was installed by double direct glue with the same carpet, he
said, the NRC rose to .55. In other words, the sound absorption tested at more
than twice the amount absorbed by carpet alone. The remarkable degree of
acoustical improvement found in the study should be of particular interest to
floor covering contractors, noted Mike Norton, principal of Norton Performance
Consulting. “People have a sense that cushion under broadloom improves
acoustics, but many don’t know how much it helps,” he said. “This study
puts some numbers to the amount of noise reduction achieved by cushion under
carpet—and the gives floor covering professionals some data to make the case
to their contract customers.
“The most outstanding result of the study
was the improvement from no cushion to cushion in the workplace was quite
significant,” he added. “So, as specifiers consider an overall program for
the workspace, this study will definitely assist them. “I know when I was
working in the corporate environment, if there was a conversation going on down
the hallway, it could be distracting,” he said. “While I don’t believe the
use carpet or cushion is the only answer, they are definitely important
components in helping to solve the problem.” “I believe this finding will
mean a lot for dealers at the retail level,” said Bill Oler, CCC’s executive
directoring. “It shows what people can expect from carpet cushion in both
workplace as well as residential applications, and it also educates people on
broadloom’s vacuumability.”
ITS also tested for IIC (Impact Isolation
Classification), the ability of broadloom with cushion to lessen the sound
transmitted from one room to the room below it. A bare concrete slab, with an
IIC rating of 19, improved to 58 with the addition of direct glue carpet. With
double-glue installed bonded commercial polyurethane carpet cushion, the IIC
rating increased to 69, a 19% improvement over carpet alone. Sound Absorption in
the Workplace, a detailed report on the new test results, can be obtained by
calling AFPF at 800/696-2373. —Louis Iannaco
