If the ceiling is textured, it might be difficult to hide any mud that gets on it, even harder to remove any spray foam as it sticks well to anything it gets on. I wouldn't expect there to be any adhesion issues with putting j/c over the spray foam. Consider filling in the gap with a wood filler.Dec 13, 2010
Can you use expanding foam to fill holes in walls?
Expanding foam is meant to fill small wall cavities that are difficult to reach. It also seals gaps to resist weather intrusion. ... When first sprayed, it is a thin liquid foam but expands to 30 to 60 times its original size after hardening.Apr 28, 2021
Can you use expanding foam to fix a leak?
Using expanding polyurethane foam is one of the best ways to stop water leaks because the foam will expand into the cracks and help prevent future leaks. ... Expanding foam bonds to any type of surface and will quickly and effectively solve your water leak problems.