Now that I'm repainting, I thought I'd take the opportunity to ease the ceiling molding and seal between the wall and the ceiling gypsum.
I want to seal it to prevent warm indoor air from rising to the cold attic and causing problems. There isn't any plastic behind the gypsum boards in this house, but the gypsum is aluminum-foiled as moisture protection. Then it's probably good from a fire safety point of view to close it up a bit there.
It looked a bit worse than expected behind the ceiling molding. I thought it would just be a small gap, but the gap is finger-wide.
I have latex caulk and this painter's caulk (http://www.bostik.se/Products/Usage/Sealing/Indoors/Products/P0215?p=03-ltr-cartridge) at home. But it's going to take a huge amount...
Maybe there's some caulk band to insert?
What is best to use for this?
I want to seal it to prevent warm indoor air from rising to the cold attic and causing problems. There isn't any plastic behind the gypsum boards in this house, but the gypsum is aluminum-foiled as moisture protection. Then it's probably good from a fire safety point of view to close it up a bit there.
It looked a bit worse than expected behind the ceiling molding. I thought it would just be a small gap, but the gap is finger-wide.
I have latex caulk and this painter's caulk (http://www.bostik.se/Products/Usage/Sealing/Indoors/Products/P0215?p=03-ltr-cartridge) at home. But it's going to take a huge amount...
Maybe there's some caulk band to insert?
What is best to use for this?
flexible joint or joint tape. even drev can work to some extent
I had skimmed,
I have just sealed similar gaps at our home, I foamed with PU foam. After curing, I trimmed it clean and for safety's sake, I went over it with acrylic sealant.
Another option is gypsum filler and then seal the corner with acrylic sealant.
Another option is gypsum filler and then seal the corner with acrylic sealant.
Where I had the largest gaps, I applied a bead of foam sealant on the molding before installing it. (It is a concave molding). Where the gaps were smaller, I used latex caulk. For me, the main reason was to create an effective barrier against the wind for flies, but it also helps with air leakage.
Brilliant!
I haven't seen any flies yet, but a wasp fell out from behind a strip, so there will be a barrier against flying insects here as well.
I haven't seen any flies yet, but a wasp fell out from behind a strip, so there will be a barrier against flying insects here as well.
I didn't manage with foam, but with latex it went better. But it didn't turn out pretty - lucky there's going to be a molding in front. 
seal and pull with sponge or jointing tool.Allinug said:I couldn't get it right with foam, but latex worked better. But it didn't turn out pretty - lucky there's supposed to be a trim for it.