Crawl-wall insulation....

[Mr T]

I'm trying to prepare for this winter's heating season (live in NW ohio-cold and windy). With hearing what nat. gas prices are supposed to do this winter, I'm trying to get the house more efficient.

We have a 2300sqr ft house that is 'U' shaped (lots of wallspace). Full crawl with a average wall height of about 4'. Gas heat, ductwork (uninsulated) is in teh crawl. Ive tracked temps down there before. Nighttime temps never get below 40, with the heat running in the day, ive seen them in the 50's to low 60's on some days. (ive found 3 ducts that have come apart so far, havent found any more yet....another project)

Did some looking into 2" blue styrofam type insulation board. $28 for a 4x8. The pink stuff (owens corning brand..duh) is $23 for a 4x8. With the size of the house. THis is going to get expensive fast!

How much heat loss/cold infiltration occurs in such a crawl? Is there a cheaper alternative (fiberglass?). Should i go thinner at half the price? Also, in the 'U' of this hosue is a inground pool with a concrete slab apron. This room is enclosed. About 2 feet of crawlspace wall is below this slab with about a foot above ground. HOw does this change things?

have fun

[mdshunk]

If you do insulate your crawl space walls, then you need to put vapor barrier on the dirt in the crawl (assuming the floor joist cavities above are uninsulated).

[Mr T]

There already is one burried under some gravel...

I'm jsut wondering if the return on the cost of insulating my crawlspace will be worth it in a reasonable amount of time (few years)

[Wgoodrich]

To give an accurate prediction would only be a guess with many variables. However using your own temp record you said 40 degrees at night. Then you have air circulation if you have vent in crawl. 40 degrees compared to 78 degrees in living area is close to 40 degrees difference. Should be obvious if crawl perimeter is insulated and vents sealed you will up the temp to average 60 degree counting on heat loss of heat ducts in crawl. Yes you will get your money back that fast or faster. However if you want better savings not only insulate the crawl perimeter and seal the vents in winter opened in the summer using scraps of that styrofoam saved from pieces not used plugging your vents, you should insulate your heat ducts if they are not already insulated. This is also a huge savings.

If you are in central Ohio you are required R 10 insulation per the IRC adopted in your state installed around your crawl perimeter just for added info.

Good LUck

Wg