Spray foam insulation cost???

Constantin

I would install the insulation on the outside of the foundation wall for all the reasons that the fine folk at <a href="http://www.buildingscience.com">Building Science Corporation</a> have listed. Make the walls inside the home a part of the thermal mass, reduce water leakage and other reasons to do so. We used 2" of XPS + Rub-R-Wall in a cold climate with heavy clay, and so far, she's tight and warm.

As for windows, I would go over this with an expert along with the architect. If you are in a climate that is heating dominated, it might make a lot of sense to choose high-R windows that also have a high solar tranmission rate. However, make sure that the uptake will not overwhelm your home and that you have some means of keeping out the summer sun. Otherwise, you'll bake.

Large windows are also problematic in the ways that cold air tends to "fall" down them, making people near them uncomfortable unless you put radiators below to counteract the cold convection and the large radiant losses through the glass at night.

Eric L._2

Spray foam insulation cost???

I am cosidering spray foam insulation (1.75/2.00lb density)in my house. Do any of you have any experience in having this done? If so what were your costs per given area/thickness (board foot)? I am having some estimates done this coming week and wanted to have an idea of what is reasonable to expect. Thanks in advance.

Eric L.

Brad White_9

Given the \"let's not talk pricing rule\"

and taking it as extending to sister trades if that is appropriate, my experience has been that the cost of spray foams (Icynene in particular) is "about double" that of conventional blown-in dense-pack cellulose.

Other foams have higher R values, Icynene being comparable to cellulose. But with foams the air sealing, moisture resistance and shear integrity is where the value is. Given a choice, I would use it. Wish I had in hindsight.....

If doing a Cost benefit analysis on R value alone, the paybacks are double. But infiltration and the absoluteness of that R value are hard to quantify. And heat loss is forever...

Constantin

Unless...

... someone has done this very recently, there likely isn't a good yardstick out there. I won't bother you with our cost for each board foot cost of Icynene and Corbond, because both of those were installed pre-Katrina, pre-oil-price-run-up, etc.

Constantin

Agreed...

... so much also depends on the kind of insulation job it is. For example, open vs. closed cavity installs usually trigger a 3x difference in cost. Nevermind trying to find a installer willing to do 2lb installs in closed cavities (very rare!)

If the OP wants to go the Corbond/closed-cell PU route, I suggest you also look at how you can reduce the thermal transfer via the studs in the house. Not much point to having R30 walls if every 16" a 5.5" Stud allows most of the potential enery savings to go bye bye.

Eric L._2

Thanks

for the info.

Eric

Jimmy Boy_2

Some help,Please.

I am doing a large addition to my home and I hope Brad and Constantin can help.Should insulation be installed on the outside of the concrete foundation wall,? or ( the basement will have radiant) should it just be blown in cellulouse in the wall studs, what about upgrading to 2x6 in the basement is there any valve rather than 2 x 4.
Oh ya Foam board or isultarp under the slab, what is the best window for a large passive solar home, I was looking at anderson 400 series, I could find any info on the insulation factor being better tha the 200 series.Thanks Brad