brankulo
New Member
Our house has low slope roofs, unvented roof assembly that consists of closed cell spray foam on the underside of roof deck plus batt insulation below that. roofing is epdm, 1/47" per foot slope. our roof is up for replacement and I am thinking of putting some rigid while they re-roof. the reason for additional rigid is non consistent thickness of spray foam. the code dictates 4" or r-20 I believe. for Denver (zone 5), the actual thickness installed is 3" and less, lots of areas with just 2" foam. we don't have any problems with moisture so far, or at least i don't see them. the only problem we had was portion of roof sheathing got spongy so i opened it up and found a mech box underneath with no foam above it as they probably couldn't get this spot. this resulted in condensation on the bottom of sheathing i believe and it got spongy. I laid some right on top of the box and sealed with spray foam so i believe this is taken care of. but I wanted to be safe and thus thinking about adding extra layer of foam. would 1.5" foam above roof sheathing be of any benefit or would i need to go much deeper?
thanks
thanks
