Stc Rating For Solid Concrete Walls

A wall system with higher stc rating is more effective in preventing the transmission of sound.

Stc rating for solid concrete walls.

1 stc sound transmission class is the usa rating used to characterize airborne noise insulation. The standard requires a minimum laboratory stc rating of 50 for party walls and floor ceilings. 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. 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.

According to the standard stc can be determined by field or laboratory testing in ac cordance with standard test methods or by calculation. An empty framed wall steel studs and a layer of gypsum wallboard on each side has an stc of approximately 35. 125 4000 hz is consistent with the frequency range of speech. Stc ratings steel stud framed walls sound transmission class stc is an integer rating of how well a framed wall attenuates sound.

Determining sound transmission ratings for masonry walls tms 0302 ref. The international residential code ref. Where w pounds per square foot psf this information is provided as a tool to help estimate. 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.

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. Stc 20 50 234w eqn. Doubling the mass of a wall assembly does not double the stc rating. One has an stc 47 4 solid concrete the other an stc 48 steel stud wall.

5 contains similar requirements but with a minimum stc rating of 45 db when tested in accordance with astm e90 for walls and floor ceiling assemblies separating dwelling units. The stc rating does not assess the low frequency sound transfer. 1 contains procedures for determining stc values of concrete masonry walls. Although that ll help you meet code it doesn t mean it s sufficient to block out the noise tenants expect.

The estimate could easily be off by as much as 4 db. Stc 0 18w 40. A wall system with higher stc rating is more effective in preventing the transmission of sound.