INSULATING CONCRETE WALLS OF GARAGE
QUESTION FROM RANDY OF SANFORD, MAINE:
I am renovating my garage and framing and insulating it. The walls are concrete block .
An architect told me to install a poly vapor barrier to the inside of the block walls, then frame the wood walls leaving a one inch space from the block. He told me to blow in cellulose into the wall cavities but I would prefer to use fiberglass batts.
Should I use unfaced with no vapor barrier on the inside or a kraft faced with the kraft towards the heated inside?
ANSWER FROM THE INSULATION DOCTOR:
Thank you for your question. I personally would disagree with your architect on installing poly between the stud wall and the block. My experience has been that when this method is used, for whatever reason, moisture gets thru the block and is trapped by the poly and you end up with mold. If you have installed the poly, I would recommend that you remove it or cut out as much of it as possible.
Then install kraft-backed fiberglas blanket in the stud spaces with the kraft paper facing toward the heated area.
Hope this helps.
The Insulation Doctor