Polyiso and WRB questions for old/new home in New England
New to this site- i appreciate the wealth of information.
Thanks in advance for any guidance.
I am preparing to apply cement fiber siding to my under-renovation 2 family home in the Boston area.
Remaining portion of original home is from 1895. first floor consists of true 2 x 4, 7/8″ pine sheathing. This portion will get open cell spray foam insulation due to the code requirements (foam will provide R18 out of R19 required)
2nd and 3 rd floor were added this summer – new 2 x 6 construction, 3/4 inch CDX sheathing. These levels will likely get R19 or R21 fiberglass insulation.
New construction windows and doors were added, and all openings were properly flashed. House wrap applied.
In the process now of adding 1/2 inch polyiso to assist with R value and quiet noise of busy road over the house wrap. I understand now that this type of insulation doesnt handle moisture very well.
Exterior trim kits for windows already built- and trying to avoid any changes to windows that would make those useless.
Looking for recommendations that (hopefully!) dont incorporate a rain screen and dont require me to make changes to window trims already built. Would doing entire interior in sprayfoam reduce the risk of moisture developing behind the cement fiber siding due to minimizing air movement from interior to exterior?
Thanks for reading!
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