New cape with simple roof. Type of cathedral ceiling insulation.
Hello everyone. I am building a small cape (22×32′) in zone 5 in NJ.
I want to ask your advice about the most “practical” roofing assembly. After reviewing multiple types of articles about cathedral ceiling insulation and discussions, I have concluded that it has to be done very well to work. And I have my doubts local contractors posses attention to detail and skills to do that.
I build a simple 12/12 pitch roof. I have three top options so far. I would be very grateful for any feedback, criticism, or suggestions. I would rather be stupid hear and ask dumb questions than in 5 years replacing a roof.
a) I’m thinking closed cell foam (R49, 7”) inside. Ice shield outside and standing seam roof. No ventilation barrier. Seems to be straightforward and common to contractors.
b) same as a, but with 2x4s over the heating to allow for ventilation to prevent ice. Does it make sense?
c) 4” of EPS over heating (R20), open cell foam (R29) inside. Drywall and spacle in interior to air seal bit allow for drying towards interior.
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