Expert: Bruce E. Johnson - 10/23/2009

Question
I have a room above our garage that i am attempting to make into a living space.  It currently has 2X4 studs with R19 insulation in the walls.  I closed up any gaps as best i can, but still have noticed that the room temperature varies a decent amount from the rest of hte house.  I was contemplating using rigid foam insulation behind the glass bat insulation on the cold side of the wall.  Is this allowed?  Also, i figure that i would have to extend the stud a little deeper so that i am not compressing the glass bat when installing the rigid foam.  What would be the best way to do that?

Answer
Hi Jason, no need for extensive furring strips and all that stuff..the newer foam insulation sheets are dense enough that you can attach them directly to the studs much like drywall and then you put your drywall on top of the foam using long enough screws to penetrate through the foam into the studs.  This is a supurb way of adding insulation factor to your room for several reasons.  One is the ease of it, no furring or stud extensions required..another is that you are actually insulating the edge of the studs which, believe it or not, can transfer cold through the wood..and it also helps cut down on any drafts coming through the walls from various places..I hope this information helps please feel free to write again regarding this or other matters, sincerely bruce e johnson..bejohnsonconsulting.com