I cant quite figure out which is going to give me the best STC rating. R15 is a bit more expensive than R13 so I wanted to check with you guys before buying the stuff. Is there a going to be a difference in STC between the two? Would rockwool be much better? I read in the rod gervias book that standard fluffy fiberglass is just as good for in-wall installation, but I've read otherwise online.
R15 vs R13 vs rockwool for in-wall with old 2x4 construction
Originally posted at johnlsayers.com, topic 16048.
It also depends on your construction and acoustic goals... In most case the pink stuff in the walls will do it. Then again, sometimes heavier insulation is called for.