Posts Tagged ‘insulation’

Spraying foam around the windows

2013-11-05 by tester101. 14 comments

One of the best home improvements I’ve made in a while, is one you’ll likely never see (unless you read this blog). And at about $10.00, it was also one of the cheapest projects I’ve done.

When the temperatures started to drop, I noticed that the second floor of my house was quite a bit colder than the first. So, I did what my mother had always done. I went out and bought window wrap, and applied it to all the windows in the house.  You know the stuff. The plastic wrap, that shrinks with a hair dryer.

Yeah, that stuff.

After spending a day installing the stuff, I noticed it was still quite cold upstairs.  As I investigated further, I found that I could still feel a draft near the windows.  So I thought to my self “The air must be coming in around the window, not through it.”.

The next day I removed the casing from one of the windows, and found a puny bit of fiberglass batt insulation stuffed in around the window.  I couldn’t believe that in a newer home, in the northern United States, this was the way they insulated around a window.  I knew what had to be done, so I hopped in my truck and headed to Home Depot. Where I picked up two cans of Great Stuff™ Window & Door, for about $10.00.

If you’re going to do this, make sure you get the stuff designed for windows and door.  The “regular” Great Stuff Gaps & Cracks may expand too much and/or too quickly, causing the window or door frame to bow out.  If this happens, the door or window may not function properly.  The window & door formula is created to expand with less force, so it will not bend the frame of a door or window.

Installing the stuff is dead easy.  Once you have the window trim removed, and the gap around the window frame revealed. You simply gently pull the trigger, and fill the gap about 50% of the way (that’s 50% of the depth, you want to fill the entire width). Run a smooth continuous bead in all the gaps, and sit back an watch it expand.



Don’t worry about being super neat, you can trim off anything that expands out of the crack later.  Use a hack saw blade, or utility knife to trim off any excess, once the foam has cured (usually about 8 hours).


Once the foam has cured, and you’ve trimmed off any overflow. There’s nothing more to do except, install the casing, and celebrate a job well done.

I found that one 16 oz. can, was enough to do two standard sized windows. You’ll also want to be aware that once you start using a can, you have to use  the whole can.  If you don’t use all the product in the can, you cannot save the remainder for later. So before you start spraying, make sure the trim is removed from all the windows you plan to insulate.


profile for Tester101 at Home Improvement Stack Exchange, Q&A for contractors and serious DIYers