Spray Foam Insulation Question

[Gkiesel]

Hello all, I'm reinsulating the under side of our Argosy from the axles forward where I replaced the front floor. Using rigid foam insulation cut and glued to the underside. Should I fill in the areas next to the frame rails with spray foam insulation? I'm a bit worried that the foam will hold water if it gets wet and promote frame rot. Any experts out there with some sage advice? Thanks, George.

[Inland RV Center, In]

Originally Posted by Gkiesel

Hello all, I'm reinsulating the under side of our Argosy from the axles forward where I replaced the front floor. Using rigid foam insulation cut and glued to the underside. Should I fill in the areas next to the frame rails with spray foam insulation? I'm a bit worried that the foam will hold water if it gets wet and promote frame rot. Any experts out there with some sage advice? Thanks, George.

Spray on foam is ok, provided you "do not" move the trailer.

When the trailer moves, the dried foam will turn to powder.

Airstream tried it, again, many years ago, and gave up on it.

It's not designed to take vibration.

Andy

[Gkiesel]

Thanks Andy, good point. I guess I won't worry about a small gap between the rigid foam board and the frame.The original fiberglass spent most of it's life laying in the belly pan. Not much R value in that. George.

[Fyrzowt]

A couple of weeks ago there was a thread running with lots of info on this subject.

[mkcurtiss]

Spray foam applied properly works great...but yes, it can hold water in the event of a leak......but you cant ignore leaks anyway, so.......Most of us are storing our Airstreams under cover anyway, so long term leaks are not a huge issue, at least not for me.....

[uncle_bob]

Hi

As pointed out a bit over 10 years ago when this thread was new .... the stuff does not hold up well in a mobile situation. RV's are *supposed* to move around ....

Bob

[Gkiesel]

Thanks MK. Forgot about this thread.
10 years on, still chasing small leaks.
Some things never change I guess.