[Greenbuilding] Sheetrock, Soundproofing, and STC Ratings

[Dan Antonioli]

I've recently had several conversations with builders, designers, and  
sheetrock contractors about various soundproofing strategies. When I  
purchased some new "Quietrock" sheetrock for a small renovation I had  
two builders grill me with questions about its performance and how it  
compares with other soundproofing methods, such as soundboard and  
resilient channel. I've looked on-line, including Amercian Gypsum,  
and haven't found an STC chart that compares the different methods.

And to make it even more interesting, I'm in a conversation with a  
builder who believes that resilient channel alone (without soundboard  
or insulation) does a lot to reduce sound. I sent him to a link that  
explains that the STC benefits of reslilient channel only is only 2-3  
points and he won't believe it. My sheetrock contractor says that  
soundboard connected directly to the framing with 5/8" rock over it  
will do more than channel and rock only. The builder disagrees with  
the sheetrock contractor and his 30+ years of experience.

I know that this has been studied and tested inside and out, so  
somewhere there's got to a chart that breaks down the different  
strategies and their STC ratings.

Dan Antonioli