Hey all, I recently moved into a newly built home with a three stall garage. Unfortunately two of the walls (not shared by the house) and ceiling are not insulated and it has already been drywalled (and crudely taped). I spend a lot of time in the garage as it is also my woodshop, but I had a question about insulation. I could take down the uninsulated walls drywall and ceiling, then insulate and vapor barrier and put it back up, but I was wondering if there were other options. My main concern is that there is no vapor barrier between the drywall and the studs in the uninsulated sections. Someone has suggested rigid foam insulation in the attic between the trusses and spray foam the seams and edges to serve as a vapor barrier. Complete spray foam is out of my budget. I have more time than money at this point, but I’m trying to avoid taking down the Sheetrock just to insulate and put it back up. I’m also in the cold and hot climate of Minnesota.
Thanks for any advice!
Replies
A lot has been written about whether a vapor barrier/retarder is necessary these days, but one thing that is necessary is the need to air seal. Without spending a whole lot of time on your exact situation, I would blow cellulose into the wall cavities and ceiling and paint the walls with a low-perm primer/paint. I think every major paint company makes one, with <1 WVP Perms. Cellulose also can hold moisture better than fiberglass and is mold-resistant, so the seasonal exchange of moisture from inside to outside and vice versa is better (that moisture holding power may not be as good in your climate). I'd also pay attention to outlets and other places to seal them as well as possible. Much, much cheaper than destruction and foam. Let us know what you decide. You didn't mention the depth of the ceiling joists, but if they're not very deep and you have the ceiling height you could add rigid foam below the ceiling to boost the R value (but that would also mean you'd have to add more drywall below it. You can figure out the cost-benefit of that.