Insulation
Hi, My wife and I just bought a 1988 Terry Resort 24' fifth wheel and we're in the planning process of renovating it. One of our first projects is to upgrade the insulation. I haven't had the chanc...
Forum Discussion
Water-Bug wrote:
If you decide to go the spray foam insulation route, be very careful. It is engineered to be sprayed between substantial residential siding and wall-board. As it expands, it can seriously bow the interior and exterior walls of an RV.
This is for the injected foam. Spray foam used in most new or reno construction is sprayed on the wall or roof surface. Closed cell has a higher R value and cures to a rigid material. If applied incorrectly it can cause damage during expansion. Open cell has a slightly lower R value, cures to a less rigid material and has far fewer problems causing damage during expansion. Closed cell is water tight and open cell isn't. Cost wise closed cell is more expensive, about 2-1/2 times the cost of fiberglas and open cell runs about twice the cost of fiberglass.
One of the biggest advantages of spray foam, either open or closed, is that it seals up all the small areas where air can seep in or out causing thermal transfers. About 2" of closed cell is equivalent to R-13 which is what you can get in a 2x4 wall. Getting all the small areas sealed actually does more for comfort than just having a higher R-value.
I had closed cell sprayed in my RV garage and open cell sprayed in my home. I actually stapled kraft paper to the upper side of the ceiling joints and they sprayed the closed cell into that. There was a little expansion of the kraft paper, but not much.
