The sheetrock per se doesn't have much R value, but it serves to seal
the inner surface of the wall, thus creates a closed air cavity in
which convention is suppressed by the fiberglass, so by not using it
you may lose more than you would expect just from the R value of the
It's interesting you should say that.
It's been explained to me that in fire-resistant safes, such as gun safes,
that several layers of sheetrock are used to protect the interior of the
Now, exactly what kind of sheetrock it is, I have no idea.
Don't even know if it's true.
If it were my garage I'd insulate it AND sheetrock it all the way around
using a double layer of sheetrock between the garage and the dwelling for
As I recall it's required in Callyfornee.
My garage is NOT insulated but is finished on all the walls and ceiling with
masonite type siding. It's colder than a witche's tit out there right now. I
wish it was heated and insulated.
Maybe someday we'll pull it down and do just that.
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