Crawl Space insulation question

Bob Bona_4

proud owner of a similar crawlspace in a similar clime (CT), here is what I'd do: 1- Yes, but you should then coat the XEPS with a fire retardant. 2-Yes. Ventilated crawls are so 1960. Treat the space as a basement, with propoer moisture control, etc. 3- Absolutely. Keep conditioned spaces isolated from unconditioned. I would recommend spray foam such as icynene over batt for many reasons,but it also has to be treated for flame resistance. Be sure you have a vapor barrier in the floor, and your outside drainage is up to snuff.

TraderH

Insulation

My home has an addition with a crawl space foundation which is open to my main house basement. The crawl space itself in not insulated but the joists for the 1st floor above have fiberglass batting (which is mostly falling down). There are hot water baseboard heating pipes traveling through the crawl space. There is also a ventilation grill, open to an unheated garage on the wall opposite the opening to the basement which undoubtedly lets in very cold air in the winter (Massachusetts). Here are my questions:

1)Should I add 1-2 inches of rigid insulation to the inside of the crawlspace walls?
2)Should I permanently close off the vent allowing cold air in?
3)Is the fiberglass batting worth tacking back up in the joists of the first floor?

I know you guys are heating experts but I bet you all know a ton about insulating.

Thanks.

KevinCorr

crawl space

If the crawl space is to be conditioned space, then you don't need insulation under the floor any more than you would need it between rooms upstairs or between any basement and the upstairs. The crawl space is insulated against the outside and kept the same temp as upstairs, then you don't have condensation and cold floors.

hot_rod

good info here

www.basementsystems.com/crawlspace/?ppc=1&gclid=CP23kc6KxpsCFZJM5Qod5zOfAg

I think this is a nation wide franchise.

Also checkout the excellent info at Building Science website.

www.buildingscience.com/index_html

www.tigerfoam has some DIY kits for spray foaming in crawl spaces, also.

hr