Using EPS for roof insulation?
I am building a home in zone 6A. It is a reclaimed barn frame that has gone through engineering, engineer wants double 9.5″ LVL’s 24″ on center. I would like to use 8″ 1.5lb EPS between the rafters giving the R value required. My thought was to spray foam the corner where the rafter meets the interior sheathing and while still curing slip the 12′ lengths of EPS in. Then sealing any other seems w/ spray foam. This would also provide for 1.5″ vented cold roof. The roof system would consist of (from interior out) pole rafters, 3/4″ reclaimed wood sheathing, Grace triflex, then the EPS block. Would this be a correct use and do you see any problems with it? Thanks!