R-Value of Roxul SafeNSound?
Does anyone know how the soundproofing SAFENSOUND product compares to the regular comfortbatt from Roxul?
Their site says:
“Roxul Safe’n’Sound is designed specifically for one purpose – soundproofing. It is not intended for thermal applications like insulating exterior walls or attics. Why? The higher density that makes it an excellent sound barrier actually compromises its ability to prevent heat loss. So if you’re objective is energy savings, choose Roxul ComfortBatt®. For a quiet home, Roxul Safe’n’Sound is the right choice. “
However if density compromises the R value, wouldn’t the ComfortBOARD be even lower R-value (the harder stuff used for exterior insulation). The comfortboard is rated at R4 per inch whereas the batt is R4.18 per inch. Makes me think the Safe’n’Sound is in the 4 to 4.18 range? Could it be lower than 4?
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It is my understanding they are the exact same product, but the safe-and-sound is 3" thick while the comfortbatt is 3 1/2" thick. After Texas' February freeze (and a broken pipe in my garage) I reinsulated some damaged walls with the safe and sound by cutting pieces of the insulation to increase depth (getting comfort batt was impossible at that time, with months of lead time).
In my experience actually installing this stuff, the Safe'n'Sound version is the same density as the regular ComfortBATT version. Their claim of "higher density" is in comparison to fiberglass as far as I know.
The regular batts are R15 for a 2x4 wall, so about R4.29 per inch. The Safe'n'Sound version leaves about a 1/2" air gap in a 2x4 wall, so it's about 3" thick making it a bit shy of R13.
BTW, the Owens Corning version of mineral has a note in the docs that they can send you a letter giving an R value for their version of the Safe'n'Sound product if requested, so that you can make inspectors happy.
ComfortBOARD is an entirely different product -- a rigid mineral wool board -- and is not comparable to either of the batt-type products.
Bill