Icynene insulation in cathedral roof
Has anyone had long term experience with using Icynene Insulation on the underisde of roof decks in a mixed climate? I’ve always been one to embrace technological advancements in construction but I guess I’m finally turning into my father and finding that old habits die hard. My application is this: reroofing my own 1920’s Colonial with a walk up attic. I want to keep the entire attic within the conditioned envelope since the a/c ducting will be there (properly insulated & sealed of course) and I was told by the installer that the underside of the roof did not need venting. I like that idea since I would have to find a way to vent the soffits which have exposed rafter tails and vents would be pretty noticable. I’m concerned that in 5 years from now we will find out that decking is rotting from the underside in applications like this since humidity can swing wildly from one day to the next for 4 months a year here. I will be installing an a/c outlet in the attic to moderate the temp swings (lowering the strain on the handler) and will be sheetrocking both the ceiling and the insulated exterior walls. Should I hang onto my ways & vent the roof with a ridge/soffit combo? or put my faith in science & seal it with foam? I will be re decking the entire roof with 3/4 CDX, 30lb felt, Ice & Water Shield topped with synthetic (rubber/plastic) slate shingles. Related question: how about any experience with syn. slate? Any problems, tricks, preferred manufacturers? I swore that my last roofing job (for a customer) was the last roof I ever did. PERIOD. Since neither my wife nor my Chiropractor can convince me to sub out on my own house, THIS will be the last roof I ever do and I want it to last at least as long (preferably longer) than I do. Thanks for any thoughts. MB
Replies
Sounds like an expensive roof. Believe the foam guy, no vents.
Joe H
In commercial work, we have been using sprayed in place foam insulation for more than 30 years without a single failure.......so take it for what it's worth.
Gabe
I like the sound of a 30 year history, especially since my understanding was that it's only about 10 years in residential applications. My question to you is this- are your commercial jobs steel frame & decking or wood/ wood construction? Thanks for your info. MB
Just about every type of construction. Wood, steel and concrete.
Recently, a 20 story building in Toronto was remodeled after 30+ years of service and the foam was still performing like new. The owners decided to not touch it and only re-do the brick veneer.
Gabe