insulating walls in my 1978 home

bsmith82 · 06-13-2009, 08:35 PM

Hello- last winter, my northwest bedroom walls were so cold, there was frost on the inside wall. some water running down etc... I could tell from the touch that perhaps one or several cavities were probably without insulation, yet when I removed the plug plate, I could not push a coathanger into the wall with out hitting insulation. Another was clearly without insulation.

I have to do something. Can I safely add blow in foam to the wall with fiberglass batts ? I am thinking of cutting a 6 " horizontal strip of drywall out to get a better picture of the interior cavity wall. I can repair the wall-I am sure- (wainscoating, beadboard etc)

Would it be ok to just blow the foam in, or should I remove any fiberglass that might be in there and has collapsed.?
Thank you for your help.

glennjanie · 08-15-2009, 05:05 PM

Welcome BSmith:
I would prefer to work on the surface of the wall by using styrofoam sheets, either on the inside or the outside. We recently used the 'fan-fold' 3/8" foam on our house covered with vinyl siding. It is amazing, how much difference we have noticed. I am in a more moderate temperature area than you though.
You could add 2" foam sheets to your inside walls and cover it with gypsum wallboard for a super barrier. Of course you would have to extend your outlets and door and window frames to the new surface.
Glenn

kok328 · 08-17-2009, 09:35 AM

It might sound extreme but, drywall and mud is cheap enough. Also with the mention of moisture, I'd want to inspect the entire cavity for mold. I'd remove the drywall from the entire wall, remediate any mold issues, reinsulate, install new drywall and finish the surface. Collapsed fiberglass is not an effective insulator and should be removed, blow foam might be overkill and is expensive.