Insulate Behind Cabinets - Small Gap!

[seanheinle]

So I've got a tricky insulation issue.  My kitchen cabinets were installed directly on the outer wall of my house (no framed in wall).  This results in a ton of cold air flowing from under my sink and bottom half cabinets.  Since the cabinet is directory against the back wall, there's only about a 1/2 inch of space between the cabinet back and the wall.  Closed cell foam seems like the best option for it's air sealing properties.

Anyone have any luck with those DIY closed cell foam kits?  Most of them look like they are for spraying on an open wall.  That's not an option for me.  I'm hoping to make a few small holes in the back of each cabinet, insert a hose/nozzle and fill it up.

Right now, my solution is to hang a curtain at the door to the kitchen to keep the cold air out.  It works well enough but ya know... I'd rather not have the curtain up for 3 months of the year :)

Thoughts?

[lthenderson]

Personally if I were you, I would use open cell foam kits for this job for a number of reasons.

1. Because closed cell foam is more dense, it can apply a lot more pressure in enclosed situations like between your wall and cabinet and could buckle panels pretty easily. Open cell foam is much more forgiving in this aspect.

2. Open cell foam expands much more than closed cell foam so you can do the job with fewer holes poked into the cabinets.

3. Open cell foam will create an air boundary just as well as closed cell foam though closed cell will have a slight thermal advantage due to its density.

When you do this, start off slow and get a handle on the expansion rates before filling up a cavity with foam and then watch buckets of it skirt out all the cracks as it expands. It is not very easy to clean up when it gets all over everything.

[AccidentalMiser]

Any reason you can’t just use cans of “Great Stuff”?  I had a similar situation and solved it with a few cans.

[bacchi]

Can you get to the entirety of the wall? Rigid foam boards might be easier. Seal the seams with a can of low expansion foam.

[lthenderson]

Any reason you can’t just use cans of “Great Stuff”?  I had a similar situation and solved it with a few cans.

This was what I was thinking about when I typed "open cell foam kits" up above. I'm glad someone pointed this out.

[seanheinle]

Great Stuff would be perfect actually. Even though I've used it all over the house to seal gaps, it never occurred to me to use it for this.

I'm assuming the maximum expansion option would be best (big gaps or whatever it is). Any reason I'd go with another one?

[zolotiyeruki]

Actually, I would NOT opt for the highest expansion, because that stuff will put a lot more pressure on the back of your cabinets and bow them in.  I think you'd probably want the low-expansion stuff that's intended for doors and windows, which don't take warpage well.

I'm also having trouble understanding why you'd have cold air coming out of your bottom cabinets but not from the wall above the cabinets. Is there no stud wall behind those cabinets?  Is there no pre-existing insulation?

FWIW, I recently did the "drill holes and inject foam" thing with the uninsulated lid of a cooler (who makes a cooler and fails to insulate the lid!?  a mfr for Walmart, of course!), and it worked great.  Drill holes, inject foam starting at one end, let it sit overnight, and break off the over-expanded bits the next morning.

[bacchi]

FWIW, I recently did the "drill holes and inject foam" thing with the uninsulated lid of a cooler (who makes a cooler and fails to insulate the lid!?  a mfr for Walmart, of course!), and it worked great.  Drill holes, inject foam starting at one end, let it sit overnight, and break off the over-expanded bits the next morning.

Good idea. Did you use the low or high expansion foam? You injected in a hole at each end?

[seanheinle]

I'm also having trouble understanding why you'd have cold air coming out of your bottom cabinets but not from the wall above the cabinets. Is there no stud wall behind those cabinets?  Is there no pre-existing insulation?

Exactly. There is no stud wall behind the cabinets.  It's a galley kitchen and the previous owner renovated.  I'm assuming they wouldn't fit the cabinets they wanted with a stud wall.  So they ripped it out and installed directly on the outer wall.

Thanks for the suggestion.  I'll stay away from the big expanding foams.

[zolotiyeruki]

I'm also having trouble understanding why you'd have cold air coming out of your bottom cabinets but not from the wall above the cabinets. Is there no stud wall behind those cabinets?  Is there no pre-existing insulation?

Exactly. There is no stud wall behind the cabinets.  It's a galley kitchen and the previous owner renovated.  I'm assuming they wouldn't fit the cabinets they wanted with a stud wall.  So they ripped it out and installed directly on the outer wall.

Thanks for the suggestion.  I'll stay away from the big expanding foams.

So what is the construction of the exterior wall, if there are no studs?  Are the walls brick?

FWIW, I recently did the "drill holes and inject foam" thing with the uninsulated lid of a cooler (who makes a cooler and fails to insulate the lid!?  a mfr for Walmart, of course!), and it worked great.  Drill holes, inject foam starting at one end, let it sit overnight, and break off the over-expanded bits the next morning.

Good idea. Did you use the low or high expansion foam? You injected in a hole at each end?

I don't think it was low-expansion foam.  I was concerned that it might force the lid to bow, so I drilled probably 15 holes in a grid pattern, and injected into each hole until I could see foam through other holes.  In retrospect, I probably could have just done one hole in each corner, and a single on in the center, and injected into the four corners in order to make sure to fill all the voids.

[seanheinle]

Yea, brick walls

[Papa bear]

So this is a plaster on brick construction?  How did they attach the cabinets? Tapcons? Do they have furring strips on the walls first?  If there's a gap, my guess is that there are furring strips attached 16" on center.  You would have to insulate each gap, which could prove difficult.

I'm not sure you're going to have the best results with expanding foam to get good coverage unless you drill holes throughout the back of your cabinets and spray in like the poster above did with his cooler lid. You might just want to air seal with caulk. Or pull the cabinets and insulate first with rigid foam board.

If you do use spray foam, good luck pulling those cabinets back down!  They'll be a bear to remove.


Sent from my iPhone using Tapatalk