Replies

1. Expert Member
   BILL WICHERS | Oct 19, 2020 10:56pm | #1

   We need a little more information about what you’re trying to do to be able to get you a good answer. If your plan is to build an unvented “hot” roof, then yes, you can do that with spray foam, but there are still some details that you need to get right that depend on your climate zone and roof structure that you didn’t mention.

   You don’t normally talk about “encapsulating” a roof, so I’m not entirely sure if it’s a roof assembly you’re asking about here, either.

   Bill

2. 
   1869farmhouse | Oct 20, 2020 10:13pm | #2

   I'm sure this was not the intention, and I'll certainly chime in to help after clarification, but all I can think about now is a house that's basically just made out of spray foam. When are we going to start just injection molding homes out of closed cell?

1. 
   DCContrarian | Oct 20, 2020 10:50pm | #3

   Google "3d printed house."

1. 
   1869farmhouse | Oct 21, 2020 07:26pm | #4

   Interesting stuff. I’m going to be building an extremely small hunting cabin next year. I seriously might consider building forms like I was going to pour concrete and pumping them full of slow rise closed cell foam. I’ll take pics if I do!!

   Edit: Would probably need to coat the exterior with that plasticized UV barrier

1. 
   DCContrarian | Oct 21, 2020 07:41pm | #5

   I don't think foam by itself has the strength. You may want to look at SIP -- structural insulated panels. Some people make their own out of sheet foam but it's generally not worth it. For a tiny building the overhead of having panels made may be so great that it pencils out.