Spray foam insulation
Has anyone used spray foam insulation on the underbelly of their fifth wheel or have any opinion on using this for insulation? Last year, somehow the insulation in the underbelly of my fifth wheel bec...
Forum Discussion
pianotuna wrote:StirCrazy wrote:pianotuna wrote:
be sure to use closed cell foam.
I would cut foam boards to below size and spray foam the edges.
I'm not sure I would use closed cell. it does have a higher insulation rating, but it is not flexible at all and if you have a leak it wont let water thru.
open cell is still r3.4/in it is flexible so wont crack in a application prone to movement, and will allow water to slowly drain if you have a leak.
Steve
If you use open cell the insulation may become saturated with water. Then when it freezes and thaws may have a right mess, including such desirable items as black mold.
it drains and dries out, that's why the building code here is starting to favor open cell foam. both types of foam are mold resistant and both types can have surface mold between the insulation and the substrate it was sprayed to due to condensation. this is more common in OSB roof sheathing though, which is why it is not common to spray the underside of the roof and turn the attic into a conditioned living space.
Steve
