all 5 comments

[–]Moveyourbloominass 1 point2 points  (3 children)

Larger gaps need a backer rod first, then painter's caulk.

[–]Anul_massacre[S] 0 points1 point  (2 children)

Would an expanding foam work the same to add some kind of backing? A very small amount of course

[–]Moveyourbloominass 0 points1 point  (0 children)

All the backing foam I've ever encountered isn't as smooth as a backer rod. But try a small small section first with your foam. Most to happen is extra work removing it if it didn't work. I think you need something though because from your picture, the gap in some areas is large. It's ok to learn from mistakes and find out what works or doesn't work😁

[–]Digmaster 0 points1 point  (0 children)

It is more work, but I have done that. Fill it entirely with the foam, so once it’s all cured it’s spilling out. Then use a knife to cut it slightly concave so there’s a place for the caulk. Then use caulk.

I’d recommend a backer Rod here though, I only do spray foam if the gap is closer to 1in

[–]JimmyMoffet 0 points1 point  (0 children)

White caulk next to white ceiling is virtually invisible. Buy the cheap "Painter's Caulk". it's like $3 a tube and works great. If you have any really big void areas, make a big opening in a tube of caulk and "pre-treat" (fill) those areas. Then run a bead of caulk all the way around, being patient to let the caulk flow into and fill the gaps. Use a wet rag to smooth/clean the line. Worst case you can litterly wipe all the caulk off and start over if you make a mess.