Even in walls made using the same material the thickness is always different.
Stc rating of concrete walls.
Standard method for determining sound transmission ratings for masonry walls tms 0302 ref.
In the absence of test data standard calculation methods exist which tend to be conservative.
Adding green glue to boths side of a wall.
The estimate could easily be off by as much as 4 db.
The magenta line in that graph is the standard reference stc contour.
The green line is the performance of the wall.
1 contains procedures for determining stc values of.
A wide variety of stc ratings is available with concrete masonry construction depending on wall weight wall construction and finishes.
Wall thickness and material.
Due to increased mass poured concrete and concrete blocks typically achieve higher stc values in the mid stc 40s to the mid stc 50s than equally thick framed walls.
Sound transmission class guidance introduction the noise guidebook.
Because coarse textured units may allow airborne sound to enter the wall they require a surface treatment to seal at least one side of the wall.
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.
There are numerous other issues that need to be addressed to get a more accurate.
Walls with a higher stc are better at blocking sound the higher your wall stc the more peace you will enjoy.
125 4000 hz is consistent with the frequency range of speech.
Helps ensure that partition sound performance matches the promise of sound tests by sealing off spaces at partition perimeters and around cutouts can increase the stc rating of a double layer steel framed partition from 29 to 53 stc an integral part of high performance usg partition designs for attenuation of low frequency sound from machinery and music suitable for use at the perimeter of fire rated wall assemblies for more information see the following brochure.
If your wall graph is closest to a standard stc 35 curve your wall is said to have an stc rating of 35.
The stc rating of a cmu wall can be estimated based on its weight using the following formula.
Stc 0 18w 40 where w pounds per square foot psf this information is provided as a tool to help estimate.
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.
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.
The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings.
A drywall wall is different from a concrete one in different properties.
