Filling gaps around windows

Dec 17, 2021 Last reply: 4 years ago 17 Replies

My neighbors recently had new windows installed and when the installers were done I noticed 3/16 - 1/4" gaps behind the window moulding to the walls.



I have used painters caulk to fill gaps like 1/16 - 1/8", but what product should I use to fill gaps this big on an outside wall ?



Thanks


Best bet is to get the hack that did the installation to do it right.

I can appreciate that answer, but they are gone and my job is just to fix it. Any idea what I can fill the gap with ?

I've used silicone caulk for wide gap and it does not shrink. Be sure it is paintable if that is the end goal.

That's what I was thinking too. If the gap is too wide and it's not working right, could put some backing material, like foam weather stripping material, in first. Actually I think 100% silicone isn't paintable, but there are products that are a mix that are. I'd try one small section first, see how it goes. You have to wonder what else hacks who did that job did wrong.

I have used silicone caulk around mine. Installer probably should have done it but did not notice. I had no problems with windows but it was the sliding glass doors with gaps I first noticed with stink bugs coming in during the fall months.

They make a round strip foam that you can tuck into the gap then finish off with regular caulk .

Spray foam in the can but be sure to get the kind in the blue and yellow can marked for windows and doors (limited expansion) or it will warp the window frame and you won't be able to open the windows. A little dab will do you. Even the low expansion stuff will blow up if you use too much.

Expanding spray foam - to fill a 1/4 inch gap ? If you say so ... John T.

What if a zebra didn't have stripes ? John T.

Use backer rod to fill the deep parts.

It depends on how much insulation you want. I assume that 1/4" gap is

3.4 - 4" deep minimum. That is the regular thing they do in new construction here to meet the energy code. Not a lot of R value in 1/8" of RTV.

The standard double hung frame is 3.5" deep and then you have furring and drywall making it more than that on a CBS wall.

Assume away.

Spraying expanding foam behind an unknown < hack-job >

window replacement is asking for trouble. especially when the OP asked for a 1/4 inch exterior caulk . My first thought was to drainage - don't caulk over the condensation drainage slots ! John T.

Drainage slots are usually within the frame, not around the edges and we still have not heard how deep this is. I really don't give a s*it anymore.

+1

That's what I was thinking of when I said they have foam product, like weather stripping. I couldn't remember what it's called.

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