Best material for insulating along (inside) basement mudsill


We seem to be having a fair bit of cold penetration along the basement mudsill (above the stone foundation) and between the floor joists.
I would like to insulate and my first thought is to use a combination of the 2 inch "pink" rigid insulation (cut to size) plus expanding foam insulation to fill remaining irregular gaps.
Any other or better suggestions before I start the project?
Thanks
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

The ideas you have sound OK. Since the draft is coming in through the floor jouist I would consider getting up there with come regular caulk and seal all the cracks where the cold can come in. Foam is only needed for really big cracks.
At that point you could just use fiberglass bats which are conveniently sized to fit in the space between the joists. It would require some type of ceiling to finish however, drywall perhaps. A finished basment adds to the function and value of the home and finishing the ceiling is a big step in that direction.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Perhaps my explanation is unclear. The area of cold is along the outside *perimeter* of the house at the level of the "mudsill" which in my old house is something like a 4x10 or so resting (irregularly) on top of a 12 inch or more stone foundation. My guess is that a lot of the air is leaking between the inevitable cracks between the irregular foundation and the mudsill. But additional cold is probably penetrating the mudsill itself since wood has a rather poor R-value.
So I was proposing to cut (irregular) rectangles of 2" pink rigid insulation to fit between the joists along the perimeter mudsill. Then since everything is rather irregular anyway I was going to use foam to seal between the rigid foam and the surrounding joists, stone foundation and mudsill.
Does this explanation help?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
blueman wrote:

Sounds like a winner. Just cut the pink insulation over size and smash into place and it will deform to make a fairly tight air seal as well as provide insulation.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Can't you get cannisters of urethane foam and just foam the entire rim?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I would love to just foam it but I am worried about two problems. 1. The spray cannisters they sell (at least at home centers) are rather expensive. Say $7-8 per aerosol can (even the pro-pack stuff is not much cheaper) 2. It tends to look rather messy and non-professional -- and I don't think it is just my application technique :)
Do you have any specific suggestions on materials or techniques that might avoid the abvoe two problems.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

They sell the stuff in, not aeresol cans, but in multigallon cannisters, (two components and some mixing apparatii (apparatae?)
And if it's an unihabbitted space, it doesn't really matter how uprofessional it looks, and if its' inhabbited, you're supposed to cover it. In any case, once it's up, you can carve it to shape with an electric carving knife.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Oh, you mean the REAL stuff :) Do you know whether you can rent the mixing apparatus for a reasonable price since I am only doing a small area so no real interest in spending big $$$ for whole-house sized equipment.

I know they sell expensive special purpose ones, but again can you either rent or get some reasonably good low-cost alternative.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Are you doing this repair from the inside? If so, I did exactly what you are proposing. The only difference is that I put a good size bead of caulking on all four seams of the space and smushed the poly board into it.
A more recent example is to cut the foam a bit smaller then the opening leaving say about a half inch gap all around and then going back with the spray foam to fill in the voids. Much easier then trying to get tight fits with the foam board.
wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
wrote:

imho:
I'm guessing as long as you aren't using the fiber glass to stop drafts. I've learned from my house, that I can insulate the heck out of something, but drafts will make areas still feel cold.
For the foam stuff, I like the dap latex stuff. It cleans up well.
tom @ www.BlankHelp.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
I prefer Icynene insulation around sil interior the R-value is much higher than fiberglass.
| wrote: | | >We seem to be having a fair bit of cold penetration along the basement | >mudsill (above the stone foundation) and between the floor joists. | > | >I would like to insulate and my first thought is to use a combination | >of the 2 inch "pink" rigid insulation (cut to size) plus expanding | >foam insulation to fill remaining irregular gaps. | > | >Any other or better suggestions before I start the project? | > | >Thanks | | | imho: | | I'm guessing as long as you aren't using the fiber glass to stop | drafts. I've learned from my house, that I can insulate the heck out | of something, but drafts will make areas still feel cold. | | For the foam stuff, I like the dap latex stuff. It cleans up well. | | | tom @ www.BlankHelp.com | |
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
On Wed, 31 Jan 2007 06:00:14 -0500, "Mark Monitor"

Agreed! Just that IC isn't a diy product, as far as I know.
I personally dislike fiberglass unless it's encapsulated such that none of it is exposed to the inside of the living space.
tom

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I was talking about the "pink" solid insulation boards -- not fiberglass batts.
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Extruded foam boards are nice, but the restrictions on using them exposed kind of makes them more complicated.
tom @ www.BlankHelp.com
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I called our town inspector and explained the intended use and he didn't have any code problems with using it along the exterior mudsill, if that is what you were referring to...
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

I read some where in the irc, that it cannot be exposed. That it can be used as an exterior sheathing(coverd with a weather proofing material), but anything inside the home requires a fire barier.
I can't remember where, but I'll look. If anyone else knows the limitations for interior use please post.
tom
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Related Threads

    HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.