I need to insulated the unheated crawl space on a new addition to my house. The space is about 3 ft. high and contains the furnace plenum, insulated heating ducts, and the waste pipes. The floor joists are 2x12s, 16O.C. I live in Virginia. How thick of insulation do I need to install between the joists?
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Where in Virginia? R 19 is good in Tennessee. Paper or foil toward the heat and above all put 6 mil plastic on the ground.
Charlie
R-19 is fine at the rim joist but simply putting r-5 foam at the block or concrete from joist level to below grade is more than sufficient. Ditto on the poly.
Todd
I think that insulating the crawlspace walls might be better and cheaper, but watch out if you use foam . You might have a code violation unless it is covered. This is somewhat of a gray area, so I don't expect everyone to agree with this.
t
foam installed on inside walls of crawlspace is allowed here. not sure why it wouldn't be anywhere else?
Todd
"foam installed on inside walls of crawlspace is allowed here. not sure why it wouldn't be anywhere else?"
Fire concerns.