How to insulate garage walls that already have drywall
Discovering that finished sheetrock and mud hide uninsulated wall cavities leaves homeowners facing the difficult choice of whether to tear everything out and start over. Without a clear path for handling empty wall spaces or missing vapor barriers, freezing winter temperatures make it puzzling to know how to proceed.
What people tried
Every workaround mentioned in the threads below. We haven’t tested any of them — and nobody here is claiming they worked.
- 1Leaving the garage uninsulated if it is unheated
- 2Having someone blow insulation into the stud bays through drilled holes rather than tearing down drywall
- 3Planning to apply spray foam insulation
- 4Attempting to use gap filler foam
In their words
Unedited, grouped by where they were said, most upvoted first within each place, each linked to the thread it came from.
“I removed the drywall in the wall between the house and unheated garage, and found this warning. The cavity had no insulation, the is a piece of drywall loosely screwed to the stud.”source ↗
“I suspect this is an air return cavity.”source ↗
“I am in Southern Ontario, and the temperature can go below freezing point in winter. My plan was to spray foam the wall, but now I am puzzled what to do with that cavity.”source ↗
Where this came up
People with this problem also raised
- 24Should I use foam or caulk to seal gaps in exterior walls?
- 2How to build a closet around exposed ductwork
- 3How to soundproof a ceiling in a rental
- 2How to fix a broken piece of cement by the garage door
- 3Can I insulate and finish basement walls if they get damp?
- 5How to match wall texture when fixing drywall patches