Filling a gap between Brick and Vinyl Windows

[hauser.jeff]

Question:

The front of my house is brick, and has vinyl windows. I noticed the other day that the caulk around the windows has deteriorated. Upon removing the caulk, I noticed that there is a largeish space between the window and the brick, that is only about 1/4" where the two meet at the window frame, but behind there is a greater void - too large to fill with backer rod.

Should I insulate this space before I replace the caulk? If so, with what? I am leery to use expanding foam because of the mess, and most window manufactuers don't recommend it.

Thanks ...

Jeff

[EXT]

I would be tempted to use some of the very low expansion foam made for windows and doors. I have used fiberglass but find that when packing it in it can be too tight or not enough, worse yet, I have found that condensation can wick through joints in the window and soak into the fiberglass insulation as if it were a sponge, where it sits forever rotting the window frame and the house framing. Just use it gently, and insert as far back as you can, extend the tube if you have to, don't over load the space with the foam, add more to any voids once it is hardened.

[Warren Block]

There are low-expanding foams that are made for windows and doors:

This is a low-expanding latex foam. Flexible when dry, water cleanup, $3-$4 a can. I've used it on many windows with excellent results and no problems.

There's also a "Great Stuff" low-expanding foam. It's a polyurethane, so if any of it goes in the wrong place, you need acetone to clean it up. Also costs more than the DAP stuff.

[hauser.jeff]

Thanks guys - I will look for that stuff on my next trip to the home centers.

Jeff

[Tim Killian]

The latex foam is made by Dap, and with recent price increases, it's now $6-$7 a can. Don't use the polyurethane foams (Great Stuff, etc.) on windows because 1) they expand too much, and 2) they are a royal pain to clean up.

[Eric in North TX]

What I do in situations like that is; take regular bat type insulation, cut it into strips and jam it in with a putty knife, leaving enough room for the caulk to seal it up. I get a little itchy, but nothing a shower won't fix, my method is simple, cheap and effective.

[BobK207]

backer rod.