Opinions on Open-Cell Spray Foam on Flat Roof With Decking
I’ve done a ton of research on the topic of Open Cell vs Closed Cell Insulation. My wife and I recently went under contract on a new house and we are nearly at the point of walking away because the builder used Closed Cell on all exterior walls but Open Cell (10”)on the roof. It is a flat roof with roof decking on top. There is NO vapor barrier installed. Our concern is that the roof plywood will eventually rot due to warm air traveling to the cold roof during the cold of winter.
This builder has fantastic reviews from all previous build and states he has done this on all builds for the last 10-15 years, but from how I understand it you may not know of an issue until you fall through the roof or when you go to replace the roof. I also spoke to the team whom installed the insulation and they state this is how they have done business on flat roofs for the last 10 years with “no issues”.
We live in Chicago (climate zone 5).
Questions for the community..
Are we crazy for walking away from the house?
Are there any recommendations we can take back to the builder for remediation?
If a vapor barrier is required, is there any way to install without ripping out all the ceilings?
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