Insulation Struggle

[emilyweav]

Hello,
I am the proud new owner of a 31' 1971 Airstream Sovereign. I am planning a gut remodel. It still has the fiberglass insulation and from pulling off a couple panels, many mice have had homes in the walls. I have spent the last two days reading as much as I can about insulation and how best to do it. I think I decided I'm going to go with plain old Rockwool and include a barrier between the interior skins and ribs to cut down on heat transfer. I read all about prodex and leaving open space and I just feel like between mixed reviews and it not being a sound barrier I'd like to keep it a little simpler. My question is do I need a vapor barrier? I don't want to ruin any of the panels or soak the rockwool, but I don't know if a vapor barrier is necessary. I'm going to be full timing in southern Michigan so weather varies greatly throughout the year. I am going to have to use both A/C and heat (probably a wood stove as well) throughout the year. What do all of the seasoned Airstream people suggest? Thank you!
Emily

[Belegedhel]

I think you are over-thinking it. There hasn't been any vapor barrier in the walls for the past 50 years, right? In my estimation, the inner skin is your vapor barrier, albeit a little leaky. If you want your interior skins to be an even better vapor barrier, then seal the places where one skin section overlaps the next, and seal the interior pop rivets.

Then again, you might want your wall interiors to be able to breathe a little, considering when the shell leaks, you will end up with a puddle of water inside your wall at the base.

good luck!

[TheGreatleys]

I don't think there is any benefit to a vapor barrier against a solid sheet of aluminum.

[rugjenkins]

I agree the others. Honestly, insulating this campers can be overthought and any insulation needs to be waterproof. Water finds a way in overtime. Even spray foam doesn't seal all the leaks. But there are great improvements one can do. I coated my interior exterior skins with a product call hytech ceramic insulating additive that I added to aluminum primer. Add your choice of insulation next. Then I added a 1/8 thermal break to the ribs(sill plate foam). All these seem to do a great job together. You can only do so much with 1 1/2 inches of space.