1 contains procedures for determining stc values of concrete masonry walls.
Stc rating for solid concrete walls.
According to the standard stc can be determined by field or laboratory testing in ac cordance with standard test methods or by calculation.
The stc rating of a cmu wall can be estimated based on its weight using the following formula.
The calculation in tms 0302 is based on a best fit relationship between concrete masonry wall weight and stc based on a wide range of test results.
Where w pounds per square foot psf this information is provided as a tool to help estimate.
A wall system with higher stc rating is more effective in preventing the transmission of sound.
Stc ratings steel stud framed walls sound transmission class stc is an integer rating of how well a framed wall attenuates sound.
The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings.
125 4000 hz is consistent with the frequency range of speech.
1 stc sound transmission class is the usa rating used to characterize airborne noise insulation.
A wall system with higher stc rating is more effective in preventing the transmission of sound.
One has an stc 47 4 solid concrete the other an stc 48 steel stud wall.
Stc 20 50 234w eqn.
Common stc ratings international building code requires 50 stc between adjacent dwelling units.
Doubling the mass of a wall assembly does not double the stc rating.
Determining sound transmission ratings for masonry walls tms 0302 ref.
The international residential code ref.
Note that in the low frequency range important for music theaters traffic aircraft and most other real world noise sources the lower stc wall is literally 30 decibels better yet lower stc.
Adding absorptive material within the partition a partition is given an stc rating by measuring its transmission loss over a range of 16 different frequencies between 125 4000 hz.
Stc ratings for wall floor and window materials and assemblies 3 appendix a stc ratings a 1 walls a 1 exterior a 1 interior a 9 wooden studs a 9 metal studs a 14 floors a 16 wood a 16 concrete a 21 windows a 24 doors a 27 exterior a 27 interior a 29 appendix b references b 1.
Although that ll help you meet code it doesn t mean it s sufficient to block out the noise tenants expect.
The stc rating does not assess the low frequency sound transfer.
An empty framed wall steel studs and a layer of gypsum wallboard on each side has an stc of approximately 35.
All too often this plenums and suspended ceilings unbaffled ducts window to window outdoors common heating units transoms and air grilles unblocked joist spaces uncaulked wall perimeters ducts piping and fixtures masonry joints.
