Waterproof Seal for a Window AC Unit

Find out how to seal a window AC unit so water doesn’t seep in when it rains. Get tips on using a temporary weatherstripping caulk that you can peel off when it’s time to take the unit out.

[mai_avatar size="40" margin_right="-4px"][post_author_posts_link before=" by "][post_date before=" — "][mai_icon icon="comment-alt-lines" style="light" display="inline-block" size="1em" margin_left="12px" margin_right="-8px" margin_bottom="-4px"][post_comments][post_sponsor][shared_counts]

LESLIE: Cindy is on the line from Nebraska with an air-conditioning question. How can we help you?

CINDY: Yes, I have central air but our upstairs does not cool very well. So we put in a window air and I’ve tried to seal it with some of those foam strips and tape and things like that. But now I’ve got some issues, like when it rains. For some reason, we’re getting water soaking through the tape and coming inside and dripping. What other thing can I use to seal that that would be more waterproof but still I’d be able to take it out?

TOM: Wow. So typically, when you install a window air conditioner, you have the window – the upper part of the double-hung window sits on top of the box and then it has sort of like wings that slide out the side of the air conditioner to kind of seal out the space between the air conditioner and the opening of the window, correct?

CINDY: Correct.

TOM: Alright. And so you’ve sealed those areas with tape? Is that what you said?

CINDY: We used some strips of foam that you put around it to fill in the gaps. So we’ve got – the wings are all stretched out and then we’ve sealed, where we have spaces, with the foam strips.

TOM: Here’s what I do. There’s a product that is a temporary weatherstripping that looks like caulk; it comes in a caulking tube. Now, typically, you use this inside your house – for really, really drafty windows – and you almost caulk them shut with this product. But you can use it in a scenario like this. I think for the summer it would probably last fine. When it dries, it kind of looks like a silicone caulk; it’s clear. But the cool thing is that when you’re ready to pull out that air conditioner, you can peel this temporary caulk off.

Now, it’s made by a number of manufacturers. I think DAP makes – Seal ‘N Peel is the brand name that they came up with. Seal – S-e-a-l – ‘N Peel. And so take a look for that temporary weatherstripping caulk, search it out online. You may have to order it at a hardware store or a home center. And that’ll be much more effective than the tape, because you’ll be able to get it into those tight places and it will really stick there and keep that water out, OK?

CINDY: That sounds perfect. Thank you very much.

TOM: There you go. Sometimes you’ve got to come up with a creative solution to an unusual problem.

CINDY: I figured there had to be something. I just didn’t know what it was.

TOM: Alright, Cindy. Glad to help you out. Thanks so much for calling us at 888-MONEY-PIT.