Insulating window frame gap..

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.
Status
Not open for further replies.

Jay H

New Member
Nov 20, 2006
659
NJ
I inherited a bunch of window insulating tools and also some other home insulating objects to insulate all the switches and outlets with this foam cutout. I also got some foam with a self stick adhesive to cover the gap between the window and the framing. I spent today taking out the window trim and insulating the gap and have been using the foam that was given to me. Would using an expanding spray foam like Great Stuff work good in this. I'm afraid that since it's really sticky, it would be problemsome if I ever want to replace my windows. I've been using the foam and anything that is really large, I'm using leftover fiberglass wall insulation and then replacing the trim pieces.... Has anybody used Great Stuff for this?

Jay
 
In terms of replacing the windows, yes you will hate the spray foam mightily when removing the old window, but it isn't a big deal, just one more thing to scrape / cut out of the way, and probably easier to deal with than most. I wouldn't let that be a big concern about whether or not to use it.

However there is a seperate issue that IS a concern... Check the formula / label on any cans you would be using next to windows or door frames, and either avoid or be very light fingered using anything that is NOT labeled as "controlled expansion" or similar terms, and described as OK for use with window and door frames. Some of the early formulations especially would expand almost w/o regard for the stuff around them and if you used to much, or if it settled before expanding, could expand enough to distort the window or door frame and cause binding.

There are now newer formulas that will only expand to the degree that the material around the space allows them to without putting out to much pressure, thus they won't distort the frames.

Gooserider
 
Use the stuff labeling specifically for windows, it is minimally expanding. That said, make sure you squirt enough in there to get a contiguous bead around the window, with no voids.

Removal is no problem. Just take a steak knife and cut around the window.
 
Goose & Sandor are correct. I used foam specifically for around windows & doors. It works great, and can be cut easily with a knife. It easy very easy to use.
If you use the other foam, NOT made for windows & doors, it WILL push the sides & tops in (especially vinyl) causing many problems.
 
Just to point out, when you use the minimally expanding stuff made for doors & windows test it out first. Some, when you use it stays very delicate and soft forever and you can really fill in all the gaps around windows with it without problems but it disintegrates on touch. For removal, just stick your finger in it. Others are very similar to "Great Stuff", and expands like crazy and hardens hard, can be sanded/painted afterward. But, that stuff be careful because even if it says minimally expanding good for doors/windows if you use a lot of it at one time to fill gaps a lot of "minimally" expanding stuff starts to develop power enough to warp. Happened to me when I installed my Bay window, I had a big space to fill around it and I went nuts with I believe 2 cans and that was the type I was using. When it was dry my frame was warped and it's been hard for me to open/close the windows of my new bay. BeGreen said I should've applied it in layers, wait for it to dry between each application that way it can't develop enough power in one application to warp. Now I know :)
 
I use the DAP latex in the blue can. The regular stuff, not the DAP Plus. Works great and doesn't overexpand. The fumes are minimal and it cleans with water.
 
I started out using the minimal expanding stuff on our windows, but it was harder to find in big cans and more expensive. Eventually I finished up the job with Great Stuff. All our windows were shimmed and nailed through the casing before applying. I applied it in layers, waiting at least 4 hrs in between applications. No warping issues at all with any of the windows, but the regular stuff does appear to be tougher. I have no idea how long the minimal stuff will last before it turns to dust, but the Great Stuff appears like it will easily outlast me.
 
I just stumbled across this thread.... I have a fairly newish townhouse, 6 years old or so. It seems massive ammounts of air leak in around the windows. If I yank some of the trim off could I expect to find large voids of dead space in there? Is that what you guys are filling in with the spray foam? I know last year my neighbor had all her siding taken off the back and it looked like all the guy did was tape all the windows off (yes... they are not taped at all apparently). I am assuming she was having air infiltration problems as well (I don't talk to my neighbors).

Also, does the little foam strips you can buy to seal where the windows open and close do any good? Been considing doing both of these things since living here but never had enough motivation.

Hmmm... I just realized, I only have trim under the sills of my windows. The rest is all drywall. Maybe thats why my neighbor did it from the outside. Although right next to me bed I have felt cold air coming out under that trim on the bottom... so... dunno.
 
There's no reason why the window can't be trimmed, it will look better. Maybe start in a room with just one or two windows. Pull the bottom sill board. Then cut the sheetrock back about 1" from the window on the sides and top. That should expose the window framing and the gap around the window. The gap should be about ~1/4". It will either be filled with insulation or not. If not, you have your culprit. Fill with foam and let it cure. The trim off excess and trim the window with whatever suits the house style.

And yes, every leak you fix will help tighten up the house. Some new window leak a lot when the wind is blowing against them. This is more common with cheap contractor grade windows. It's a shame to see this on a 6yr old home.
 
The windows are basically recessed into the wall.... I think I might have some pics around

Yes the walls are green and ceiling is yellow. Thats "Frog Green" and "Street Light Yellow" Disney colors to be exact. I took these pics just after we finished painting and they happen to show the windows quite well. The windows I'm sure are "cheap contractor grade" as is everything in this place.
 

Attachments

  • 100_1203_l.jpg
    100_1203_l.jpg
    42.1 KB · Views: 666
  • 100_1207_l.jpg
    100_1207_l.jpg
    38.6 KB · Views: 641
Yep, that would be a challenge. You could pop off the bottom trim on a window to see if they filled the void at all. But not too much else you can do there but inspect for gaps where the window meets the interior recess.

Let me guess the carpet color - stop red?
 
No... normal carpet. But the closet is a melon orange color. We bought it for the hallway but decided it was way too bright.
 
Definitly the blue can of dap. I am slowly replacing windows in a 1950's ranch and what a difference the windows and the foam arround them make. It is such a difference that there is a 3 degree plus difference when its 0 degrees out!!!
 
When I remove my trim, most of my windows are fairly tight, i.e. at most a 1mm gap but it still is a gap and I've been slowly going around and filling it up with foam insulation. The great stuff will be saved for the larger gaps when I discover them. I have also started to insulate the backsides of electrical outlets, electrical switchs and stuff too since they are also typically uninsulated gaps in the drywall.

Jay
 
That is not bad unless the wind is howling. Then any gap is noticable. I think with the fireplaces burning inside air...although not a lot...you notice it more pulling air in the cracks and crevices. I know this year I need to weatherstrip the door. Just never got arround to it last year...isn't wood heat great...just throw on another log!!!
 
Status
Not open for further replies.