Roof rigid foam – paper faced vs. foil
Been lurking here for a while, but first time posting.
TLDR version: I’m planning for two layers of polyiso on a vented roof deck w/ asphalt shingle roof…bottom layer 3.5” and top 2.5”. Should both layers be foil faced, paper faced or mixture of both?
Inside to out:
rafters are going to be sistered 2x6s
1/2” existing sheathing
peal and stick
lookouts for overhangs (risinger build style)
2×4 on flat @ 16” center for vented roof deck
House will have 3.5” polyiso on exterior walls with 3/4” rain screen vented to soffits up the roof deck. Can I eliminate soffit vents if the roof can pull air from the base of the siding?
I’m in the planning stages of an exterior remodel in a neglected 1960s home that we just purchased. The house is in need of a new roof and new siding. Working with an engineer for details to ensure the roof can support the weight of the new roof to convert to an unvented attic. Wanting to take advantage of current rebates and move toward an all electric house in climate zone 5.
thanks everyone for your feedback
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