missingegg
New Member
- Joined
- Nov 6, 2022
- Messages
- 26
The issue with using polyiso and spray foam in a trailer is flex.
Spray foam hardens and becomes brittle, it will seperate from the trailer and allow gaps and air and moisture will invade.
There is some spray foam that remains flexible, permatex? Not sure... but that might be an option. Otherwise, butyl sealant for the seams to remain air tight.
The aluminum skin might be a high quality radiant barrier if an air gap is maintained. No point using foil faced foam when it's inside an aluminum wall.
Excellent point! I should have said: Although there are DIY spray foam insulation kits, you really do want a professional spray foam contractor for a job like this. There's a wide variety of chemical formulations for spray foam, and you want a foam that both has good adhesion to whatever material the trailer skin is made from, and also a little flex to stand up to the flex and vibration that a building wouldn't experience. A good spray foam contractor can help you select the right foam. Or potentially tell you that spray foam is a bad idea for the project.