Questions regarding insulating a 1912 double-wythe brick building
We have a 1912 brick schoolhouse that we are renovating in Michigan. We just demoed the entire floor system including joists and main beam due to extreme powder post beetle and moisture damage.
We are planning to reuse the masonry joist pockets for the new floor joists and plan to encapsulate the crawl using closed cell foam on the interior foundation walls, cover the soil with a 27 mil polyethylene liner and spray joists where they enter masonry pockets. We plan to close off the (2) crawl space vents on the EXTERIOR and condition the crawl space. (heat & central air). Firstly, I am concerned about the end of the floor joists which will be in the cold airspace between the wythe. Should I be wrapping them with sill seal, spraying them with undercoating, etc?
On the main floor interior of the building we have exposed brick on 3 walls, and plan build a stud wall and insulate with closed cell foam on the remaining wall. We also plan to use 1-1/2″ EPS foam on the EXTERIOR and cover with house-wrap and vinyl siding. Our thought was that by insulation the exterior we will circumvent freeze thaw damage to the brick and provide some insulation for the building. I am wondering if I should leave the (2) crawl vents open on the INTERIOR so that the conditioned air would be able to circulate between the wythes which may protect the ends of the joists as well as provide some heat to the exterior bricks–or could this cause a problem with the conditioned air going up to the attic? I am not familiar with how the double wythe walls terminate in the attic, but assume they are open.
Any comments would be appreciated. There are so many schools of thought on insulating brick buildings and our local contractors also have differing ideas. Thank you.
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