# insulation for 2' x 3' x 1/4" gap



## Bumper1234 (Feb 14, 2016)

I want to insulate the space between my kitchen counter and the exterior wall. It can only be accessed from the top of the counter. The gap is 1/4" wide. Does anybody have a solution?


----------



## Windows on Wash (Aug 30, 2011)

Closed cell, low expansions, spray foam. Tape off the area on your counter top to avoid any contamination.


----------



## Bumper1234 (Feb 14, 2016)

Thanks for the suggestion. This is uncharted territory for me so I hope you won't mind a couple of more questions. The counter is 3' high and approximately 8' wide. (I said 2' because the counter is screwed to the wall at 2' intervals and I assumed I would be using some kind of solid insulation.) Is spray the solution for a space this large? Will the spray go down to floor level and then slowly rise?


----------



## Bud9051 (Nov 11, 2015)

No, the spray foams up too quickly to get very far down. I have no experience with it, but have read there are pour in slow rise foams. Your Google would be as good as mine. But, once in there I would hate to remove those cabinets. 

There are also sheets of thin insulation, but it would not be a tight fit.

Let me ask, why?

Bud
Also, there is perlite or vermiculite that can be poured in, as long as there are no holes where it can leak out.


----------



## joecaption (Nov 30, 2011)

Very strange question.
Never once heard of anyone insulating a counter.
Why is the outside wall not insulated enough?
Why is there a 1/4" gap?
A picture would be a big help.


----------



## Bumper1234 (Feb 14, 2016)

This is an old house in downtown Toronto. Built in 1880. The outside wall abuts the neighbor's outside wall so it is inaccessible. It was never insulated and to do so would require a lot of demolition. 

Our kitchen counter was screwed to the drywall but there is a gap between the back of the counter and the drywall, probably because the outside wall isn't level.

I've attached a picture. The gap is between the top of the counter and the rear wall.


----------



## Bud9051 (Nov 11, 2015)

I'm not sure there would be a big advantage of filling that gap vs just sealing the top. Air is actually a reasonable insulator and the transfer of heat from your cabinets to that outside wall through that gap is slow due to needing convection.

I did a little reading on pour in foam insulations and they warn about expansion. Plus, it is far too cold to be installing foam other than rigid.

Perlite is still a good option as it would fill completely and cleans up with a vacuum. Here's a link for reading: https://www.perlite.org/industry/insulation-perlite.html

Bud


----------



## Bumper1234 (Feb 14, 2016)

I need the space filled because the dishwasher is under the counter and it freezes up in extremely cold weather. Perlite looks promising. Thanks for the suggestion.


----------



## Windows on Wash (Aug 30, 2011)

I would not use the foam in that long a gap. Based on your first post, I was under the impression you were just sealing the gap at the counter stop. 

Stop the air flow and that will probably give you most of the improvement you are looking for like Bud mentioned.


----------



## Bumper1234 (Feb 14, 2016)

thanks. As I mentioned earlier I need to fill the entire space so perlite sounds like the best bet.


----------



## Windows on Wash (Aug 30, 2011)

Should work.

I would still cap the top for air seal as well.


----------



## Bumper1234 (Feb 14, 2016)

Will do. thanks.


----------



## Gary in WA (Mar 11, 2009)

If you are insulating that gap, it may be the "tip of the iceberg" because if the counter-top installer couldn't scribe it to fit the out-of-plane wall (wavy), that tells us the cabinets are also pulled away to line them with the worst cabinet base unit (closest to kitchen). You may need to buy a lot... add some foam outlet covers as well as insulation board (not foam) behind the dishwasher.

Gary


----------



## Bumper1234 (Feb 14, 2016)

Thanks, Gary. Do they make insulation board thin enough to fit into a 1/4" gap? I haven't been able to find any


----------



## Gary in WA (Mar 11, 2009)

I added extra fiberglass around mine, when I installed it in my island. Helped a lot. It can be thicker than 1/4" behind the unit... just caulk the countertop joint after using some backer rod first. 

Gary


----------



## Bumper1234 (Feb 14, 2016)

thanks, Gary.


----------



## TheoKiriopoulos (Oct 4, 2016)

I would say spray foam, as it is excellent at getting into all nooks and cranny's companies don't normally come for such small jobs, but i used these guys for a small job (around the same size) and they had no problems doing it. http://torontosprayfoam.site/


----------

