Sealed cathedral ceiling in NC – foam contractors
Hello! First post here! Martin recommended I post my question here.
We are in the Charlotte, NC area, and have a pretty simple cathedral ceiling construction in our family room that hasn’t been closed in yet. The room is approximately 22×16 and has a 12/12 pitch, 16″ eaves, 2×10 rafters 16 O.C., architectural shingle roofing over 15 lb (or 30 lb?) paper, and 3/4″ OSB roof decking. The roof is part of an addition to the home, which is a historic home, so we elected to not use a ridge vent and opted for a sealed roof design so visually it looked more like the rest of the roof when it’s all done. We plan on simple drywall for the finished side.
I have had a couple spray foam installers out to talk to us about their systems, and based on articles here (and other places) I haven’t heard anything that aligns scientifically to studies that I have read. Unless I’m deciphering the articles wrong, it seems our best option for a sealed type cathedral ceiling is to have closed cell foam installed directly to the bottom side of the roof decking to the proper R30, or better, value. One company that came out wanted to install open cell foam right to the decking. Another wanted to install an air gap system with closed cell under that (even though we don’t have a ridge vent to allow the gap to work). Neither of these seem to be the correct solution, and I’ve since scheduled yet another installer to come out and may ask a forth.
Am I missing something here? Am I misunderstanding the science of how this all works? Do these installers not understand how the science works for cathedral type construction? Or are the concepts they advertise something that will work in a North Carolina climate? If I DO understand this correctly, then maybe someone can recommend an installer in the Charlotte area that knows their stuff. If I’m confused, set me straight! I want to understand this before I go any further and make a big mistake.
Any help would be appreciated, even if it means you’ve gotta’ set me straight! Thanks for your time!
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