I have an unheated, open basement in which the rim joists are not insulated. I want to insulate them but wasn't sure what the best way to do it is. At first I thought I'd use the spray foam and do it myself but the materials are expensive and I've read that you need a respirator an dmachine and the whole nine yards. Now I'm thinking it might be better to use the rigid board. I understand you still have to foam it in place. has anyone done this? Would you use a can of great stuff for something like this? I was thinking that (2) two inch pieces of rigid foam should get me to roughly R14 which from what I heard is reccomended for rim joist insulation in most areas. Any thoughts?