STUDS: Light gauge steel vs. wood w/ RC8

Hello, can anyone verify this? Load-bearing steel studs behave in much the same way as do wood studs, but lightgauge non-load-bearing metal studs are flexible enough to reduce sound transmission through the material, and provide about the same sound reduction as wood-stud walls with resilient metal channels on one face. Thanks.

Dig into the BBC RD papers. and NRC papers. There are several dealing with laod bearing and non load bearing walls and their sound isolation performance. Actual test results, not educated guesses! Andre

Thanks Andre, I actually pulled that quote from an NRC paper titled "Control of Sound Transmission through Gypsum Board Walls": http://irc.nrc-cnrc.gc.ca/ctus/ctu01e.pdf

heavymetal wrote:

Thanks Andre, I actually pulled that quote from an NRC paper titled "Control of Sound Transmission through Gypsum Board Walls": http://irc.nrc-cnrc.gc.ca/ctus/ctu01e.pdf

It is hard to get into details but they can take up pages of psots. Look ateh Tl values, not jsut the STCs. Andre

heavymetal wrote:

Hello, can anyone verify this? Load-bearing steel studs behave in much the same way as do wood studs, but lightgauge non-load-bearing metal studs are flexible enough to reduce sound transmission through the material, and provide about the same sound reduction as wood-stud walls with resilient metal channels on one face.

Ok - consider it verified............ but - What this actually translates to is better STC ratings - significant increases in isolation in higher frequency ranges - and decreased isolation in frequencies below 100 hz. - for example - comparing NRC-CNRC designs 2G13_WS90(406)_CFL90_2G13 WITH 2G13_WS90(406)_CFL90_RC13(610)_2D13 (These are both 2x4 walls - 16" on center - 2 layers of 1/2" drywall each side with 3 1/2" of celulose fiber insulation blown in - the one exception being the addition to one side of the wall with resilient channel at 24"o.c. (the RC13(610)) - and at 50hz you lose 3.1 db of isolation - at 63 hz 6.4 db and 80 hz 3.9 db - ALL FROM ADDDING THE RC TO ONE FACE - yet the weighted average of isolation in frequencies ABOVE 80 hz takes the wall from STC 38 to STC 54. The point here being that if low frequency is going to be your problem - then heavier framing and no RC with added mass is better than lighter guage metal with the same mass. If you're building double wall construction as opposed to single wall - then the difference is even more pronounced. The bottom line here is this - MASS isolates low frequencies - and the more rigid the better (generally speaking). (I note that because I can provide data for 2x4 walls at 16" providing slight increases in LF isolation over walls at 24" o.c.). I have (just for the record) quoted the data indicating this previously on this forum. Rod

Andre + Rod, Thanks for the feedback. Olivier :D