PUTTING R 25 In Footer Sill

SHORTGUN

I would like to insulate the sill above my footer and would like to use R 25, would I save on my Energy Bill and keep the house warmer in the Winter and cooler in the Summer? or

thom

Give us a hint, how do you intend to do this.

SHORTGUN

You will put the insulation between the Floor Joists, all the way around the basement.

KentWhitten

I don't mean to sound rude, but you're talking about 3 or 4 different things there. I'm assuming you want to insulate your foundation a little more than what it is. R-25 is way, way overkill. R-10 rigid insulation is all you'd ever need (unless of course you have a similar house like mine, with an old rock foundation with holes everywhere). This is usually put OUTSIDE of the foundation against the wall.

Inside, you're looking at either batt insulation against your rim joist or rigid. If you're looking for your interior walls also, unless you really know what you're doing I'd advise against it just because of the mold or moisture possibility doing more harm than good.

And insulating your floor is really only good if you have a crawl space or you're trying to reduce noise. For heating purposes, your ROI would be probably decades. If your floor is cold in the winter and you have a generally good concrete foundation, then I'd say you have some air infiltration going there which would be better served finding the cracks and sealing them.

There is a product out there that's a roll on application that's kind of insulation to some extent. I don't know much about it, but one job I was on here in the cold Northeast, they applied this product, which is essentially a paint with some type of ceramic (maybe?) on the outside of a metal building and in the dead of winter on the inside, you could put your hand on the metal and it was still warm. Amazing stuff.

__________________
If you correct your mind, the rest of your life will fall into place ~Lao Tzu

Custom Cabinetry - Portland, Cape Elizabeth, Scarborough, Kennebunkport, Yarmouth, Falmouth, Cumberland, Ogunquit, Maine

Salmon Falls Cabinetry

thom

You are describing insulating the rim joist area or the mid floor. Either way, you aren't providing an r-25 sill. The rim joist is really no different than a wall. Insulate the exterior rims the same way you insulate the exterior walls.

If what you are talking about is insulating the floor above an uninsulated crawl space, r-19 should be fine, r-25 will be fine also, not much more expensive nor much more effective.

SHORTGUN

The area that I am talking about is 8" inches high and it is where your floor is nailed to that runs all the way around the house, I call it the sill you may call it the correct name. But I feel that this area lets allot of cold air in or even warm air? I do not want to insulate the whole floor or the whole basement walls. Just the area that runs around the outside wall that the floor joist sets on.

I hope that this makes things much clearer.

KentWhitten

yes, that's the rim. the rim sits on the sill. I know, stop being picky. If you do not have sill sealer between your concrete and the sill that your joists sit on, there is more than likely a lot of cold air coming in. Air infiltration will kill you worse than no insulation. If you can get a caulking gun up there, caulk that joint good.

R-19, R-21, R-25, they're all good. You're not spending a fortune insulating just the rim, so I'd go ahead and get the R-25

__________________
If you correct your mind, the rest of your life will fall into place ~Lao Tzu

Custom Cabinetry - Portland, Cape Elizabeth, Scarborough, Kennebunkport, Yarmouth, Falmouth, Cumberland, Ogunquit, Maine

Salmon Falls Cabinetry

SHORTGUN

Thank-You framerman

One last question I hope, there are so many types of caulk on the market chap ones and very good ones, I personally lean toward your very good ones.
You get what you pay for.

Could you gave me some names of the top of the line caulk to use on this?

An I will put that R-25 up there.

thom

great stuff

KentWhitten

yeah, great stuff too, the spray foam cans. Caulking? Not sure really, I'd have to believe it'd be something that would adhere to both concrete and wood, but I'd say most do. I don't think it's critical, go ask (pfffft!) the guy at HD or Lowe's. They MIGHT know. Just grey latex caulking I guess. I know, there's millions.

__________________
If you correct your mind, the rest of your life will fall into place ~Lao Tzu

Custom Cabinetry - Portland, Cape Elizabeth, Scarborough, Kennebunkport, Yarmouth, Falmouth, Cumberland, Ogunquit, Maine

Salmon Falls Cabinetry

superjay5

I just got doing this to my house, I used 2" rigid insulation doubled it up, and then used great stuff foam to seal all the way around it.

Should stop any air leaks, and won't have to worry about mold, plus if you can double it up like I did, you can get R-20

SHORTGUN

What R factor did you use? Remember I am using R 25 so I should have R 25 not R 20 right?

superjay5

If you are using R-25 then you will have 25

I used 2" rigid foam board the pink stuff, which if I recall right has I think r-10??? But I was able to double up so I had four inches of foam. I cut it up roughly to the size of the cavity and then I ran a bead of great stuff expanding foam all the way around the foam to seal it 100%.

I went this route just because it really seals up that cavity perfectly, stops any air penetration, and it doesn't itch!!!!!