Should I Insulate The Floor of a Crawl Space
I have a ~200sq foot crawlspace under a section of my home connected by an approximately 4ft by 3 foot opening to the full basement (32’x25′) which has decent ventilation and is unfinished. Currently the crawlspace is a dirt floor with poured concrete walls. The home is from 1916 and is in New York( Zone 5). I’ve been looking to decrease air leakage and increase home comfort by encapsulating the crawlspace and adding spray foam along the walls and rim joist. In the larger basement only the rim joist will be spray foamed in all areas where spray foamed I’ve requested a thermal barrier paint.
One contractor I had bid on the job is suggesting I use thick rubber (60mil EPDM) instead of plastic on the dirt floor and then apply 2 inches of spray foam on the entire floor in addition to the walls and rim joist. I was wondering would it make sense to tell the contractor to not apply the spray foam to the floor and leave it just as the vapor barrier? Also is EPDM OK for this use? Is it better to have the foam starting about 6-12 inches up the wall overlapping over the floor vapor barrier? The quoted price is not really different from the other quotes for plastic over the dirt with no spray foam on top. Is there any disadvantages to spray foaming over the floor if it costs the same amount?
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