Looking for a replacement for old bubble seal on double-hung wooden windows

Question

Hi.

I'm looking to replace bubble seals on 20-year-old double-hung wooden windows. The bubble diameter of the old material is 1/4 in., and the base extension is also 1/4 in. (See photo.)

I'm trying to get a tight seal on gaps that run along the bottom of the lower sash and top of the upper sash. They are as wide as 7/16 in. and even 9/16 in.

It appears that the widest bubble seal I can buy for windows is 3/8 in.

What do you recommend for a durable material and configuration to seal such wide gaps?

Can I use a seal such as a kerfed, high-reach compression weatherstrip designed for use with doors? I've found one that reaches about 5/8 in.

Thank you.

Dave

Tom · Accepted Answer

Thanks for reaching out to us, Dave. I hesitate to recommend using door seal on a window, but if the gap you're dealing with is that big then you may not have a choice in the matter.

One possible replacement option would be our 58-056E. This has a .490" foam seal, but my main concern is that it would be too big to fit in the window slot itself. There are no guarantees.

Profile view of 58-056E

Since your windows were originally made with a smaller bubble seal, there is likely something else at play here. Your long term solution should be to try to find what is causing the gap and take measures to fix it. Since the window is old it may very well be a result of the frame settling.