Foundation Insulation Suggestions

[scott_vt]

Good Afternoon Guys,
I just bought a new wood stove, and while reading through the manual, it mentions that your foundation walls should be insulated, so as to minimize the amount of heat that is required to offset the heat loss on those walls.

BTW, I really knew all along that it should be done but never really got around to it ! :ashamed:

This is my Ct home, and Im only planning on using this stove here for a few short years, and then bringing it up to my Vt home...

Most of the walls are below grade, but on the left side of the house I have maybe three feet of exposure...

I really dont want to stud out the basement walls and insulate that way, and I dont want to use foam board, because of the flamibility isssue with that material...

I talked with one fella that stated that Dow Corning did have some material that could be used that was not flammable, but I havent been able to find it yet.

Im looking for suggestions, and what others have done in their basements !

 

[2manyrocks]

I think there is some sort of material like insulated duct board that is essentially compressed fiberglass. It is also used for acoustical insulation.

 

[dmccarty]

We used EPS one inch board in two layers underneath the slab and one layer on the exterior walls. At the time the foam was rated at R5 or R7. There was adjustment made around the time we used the board that lowered the R value.

We had to use EPS since it could handle the weight of the slab. But I don't remember finding another foam product that had a higher R value.

The foam insulation is expensive compared to blown insulation or batt.

It will be interesting if the TBN Brain Trust knows of a product that insulates well, cheaply, does not burn and does not take up space.

You did not spec cheap but I figured I would save you the bandwidth.

Later,
Dan

 

[scott_vt]

Good Evenin 2manyrocks & Dan,
Thanks for the input guys, I will find what Im looking for eventually, or it will be time to buy some studs ! :laughing:

 

[bdeboer]

Check out the buildingscience.com website, they address moisture as well as heat transfer.

Plone —

 

[scott_vt]

Check out the buildingscience.com website, they address moisture as well as heat transfer.

Plone —

Good Evening Brian,
Thanks that is a great link, just started to read some of it, and it looks very good !

Lots of reading by the looks of it !!!

 

[dmccarty]

:thumbsup: on the link to Building Science. We built our house with the details in one of the books from them. They know their stuff.

Later,
Dan

 

[MikeD74T]

Good morning Scott, At my place in Lancaster NH, which as you know gets cold, I put 2" blue styrofoam on the outside of the foundation from sill to 24" below grade. 48" total. I had metal flashing bent to hold the top of the foam. Top of insulation cut to 45 degree to shed water. Flashing attached to sheathing & bent down at 45 degrees then vertical for another 1/2". At -45F my basement is 80F with the wood stove going & stays above 50 when we're not there & first floor propane heater is running. The outside of the foam is covered with a cement based brush on coating for UV protection. Only problem is that finish (and foam) is not weed eater proof. I trim around the foundation with Round-up. MikeD74T

 

[2manyrocks]

First I heard of it, but there was some discussion in this thread about some kind of resin product that resists weed eater damage: http://www.tractorbynet.com/forums/related-topics/167399-parging-foundation-insulation-new-post.html

 

[Slackdaddy]

I have an unfinished basement, that I had them install the white basement insulation blankets on. These are a FG insulation with some type of fireproof white "sheet facing".
I epoxy painted the floors, painted the steel beams and with the white batt walls it looks good and is VERY toasty in the winter with no heat vents down there.

Nick

 

[heehaw]

i have never seen it done: but have heard that cellulose can be sprayed on "crawlspace" walls to insulate them: same way its sprayed into walls on new homes.
heehaw

 

[scott_vt]

Good morning Scott, At my place in Lancaster NH, which as you know gets cold, I put 2" blue styrofoam on the outside of the foundation from sill to 24" below grade. 48" total. I had metal flashing bent to hold the top of the foam. Top of insulation cut to 45 degree to shed water. Flashing attached to sheathing & bent down at 45 degrees then vertical for another 1/2". At -45F my basement is 80F with the wood stove going & stays above 50 when we're not there & first floor propane heater is running. The outside of the foam is covered with a cement based brush on coating for UV protection. Only problem is that finish (and foam) is not weed eater proof. I trim around the foundation with Round-up. MikeD74T

Good Afternoon Mike,
That sounds like a very good suggestion also, sorry for the delay getting back to you !

Home Depot has that 2" pink stuff, and if I can find a good covering for it, that may work out fine !

 

[scott_vt]

Good morning Scott, At my place in Lancaster NH, which as you know gets cold, I put 2" blue styrofoam on the outside of the foundation from sill to 24" below grade. 48" total.. MikeD74T

Good Afternoon Mike,
Im thinking this is the way Im going to go also !

Any particular reason for the 2' below grade

? Im sure your frost goes deeper than that, but down here at my Ct home 2' or even 1 1/2' would probablly work well.

The only place it would be a problem is on the far side of the cellar, I have a 2 car garage and that is paved on that side of the house but there is only about a 1' of exposure over there.

The matal strips sound like a good also ! Im thinking of that coating that looks like concrete or just gray paint.

 

[MikeD74T]

Good Afternoon Mike,

Any particular reason for the 2' below grade ...

Im sure your frost goes deeper than that,... quote]

My building has a concrete /stone foundation that was formed on the inside only with 3 courses of block up to ground level. I raised the building another 3 courses. The only way to use foam more than 2'below grade would be to clean the rough wall & spray foam. My building usually has good snow cover for at least 10' around the house so frost doesn't go very deep unless it's a bare winter. I keep the snowmachines, etc, away from that snow. Going deeper with the foam would be better but there's a diminishing return there somewhere. MikeD74T