How to repair walls “bulging” from spray-in expanding foam
A few years ago, we had a company spray closed-cell foam into our already finished exterior basement walls. Construction is 16″ OC steel studs covered with 5’8″ drywall, taped, mudded, and painted. To get access, we cut an ~18″ high opening in the drywall midway up the wall around the outside perimeter of the basement. Company then sprayed foam into each stud bay, filling from the top down and the bottom up.
After giving the foam a couple of weeks to cure, we patched up the 18″ opening and repainted. Within about a year, the walls all started to expand and bulge along each stud. Some of these “bulges” stand at least 1/2″ proud (or more) of the surrounding area.
I’m debating the best strategy to correct this damage. I thinking I will knock down the highest spots, cover in FibaTape Crackstop mesh, and skim coat the entire wall. Thinned compound applied with a roller and then skimming with a 32″ blade.
Thoughts? Better ideas?
~John
Replies
1/2"!! Best you start all over and do it right.
Only problem with that is that the backside of the existing drywall will be stuck tight to the foam! Don't think I wanna mess with trying to get that off.
So
Bulging "along" the studs? Between the studs?
If it's between the studs and there's room and no door and window trim, I'd put 1/2" or 3/4" furring along each stud, then 1/2" drywall. If there are trimmed doors or windows, you'll need jamb extensions, 1" or 1-1/4" (furring + drywall.)
In any case, I'd call the foam contractor- they should have used low expansion foam and installed it in layers to avoid bulging the drywall- that's an issue foam contractors should be aware of. The year delay on the bulging is hard to explain.
shimmed furring strips and new drywall over the bulging wall