insulating field stone basement + crawlspace

[philupthegastank]

Hi There,

I have a house that has a field stone basement, probably around 800 square feet, the walls are around 18" thick. THen attached is a crawl space where cold air just comes pouring in. What is the best and greenest way to insulate the basement, if there is a way, and to insulate that crawl space. Right now i just have packed in fiberglass insulation under the joists to try to stop the air from pouring into the basement.

Here is a picture of the basement, and the floor joists, the crawl space is to the left, where the carboard is stuffed into the wall behind the red pex.

In march of last year we put in all new copper pipping and pvc and moved the bathroom from where the crawlspace was to the interior of the house.

 

[mass_burner]

Is it ever going to be a living space?

 

[philupthegastank]

oh gosh no, but the climate im in, it can get down to -30F, and i really want to stop all that cold air from coming into the basement from the crawlspace. Anything to keep the house warmer.

 

[mass_burner]

i have a similar small area, but not stone, where cold air comes up into a part of the kitchen. I was recommended spray foam in the rafters as long as it was only a pass-through area, not living space.

 

[semipro]

This article at Building Science covers this.
(broken link removed to http://www.buildingscience.com/documents/bareports/ba-1108-hybrid-foundations-retrofits-measure-guideline)

In general there are two options.
Isolate the house (including basement) from the crawlspace or
unite the crawlspace and living space and isolate both from the environment.
Seeing that you have plumbing and a water heater down there the latter is your best bet.

 

[begreen]

Is the crawlspace ventilated and if yes, are the vents sealed closed in the winter? That would be a first step. Maybe put a gasketed and insulated door to the crawlspace connecting passageway?

 

[sesmith]

More here.

http://www.buildingscience.com/documents/insights/bsi-041-rubble-foundations/?searchterm=rubble

 

[philupthegastank]

thanks for the replies and links!

 

[Circus]

I bet if you crawl into the crawl space and apply some steel bulding insulation against the stone wall it would cut down on drafts and cold. You could seal the bottom with dirt and wood strips along the top and between the joists at the sill.

 

[Ashful]

Drafts aren't coming thru the stone, Circus!

Sills and joist bays are the issue, but if you can feel cold air rushing in, you need to find the exterior point of entry and block, lest your spray foam become a wonderful and cozy mouse den.