Century home owner seeks ways to stop basement window drafts

"How can the window and sealed crawl space be weatherproofed?"

A homeowner getting ready for a fourth winter in a 111-year-old house asked other century-home owners for guidance after basement insulation did not eliminate a persistent draft.

With one wooden window still allowing cold air inside, they looked for a seasonal solution and posted the question in Reddit's r/CenturyHomes forum.

Here's what to know

In the thread, the homeowner said the other three basement windows had already been replaced with vinyl, leaving only one older wooden window that was still letting in cold air.

The original poster wrote, "Our basement gets colder than it should and last year we had the floor joists and basement ceiling insulated. … My question is how would one go about weather proofing the window and sealed crawl space?"

Commenters quickly offered ideas. One popular reply recommended, "Look at indow windows interior storms. Yes, that's spelled correctly. Much nicer than most of what's been suggested so far."

Another commenter advised beginning with the frame rather than the glass: "Caulk and weatherstrip the window perimeter, then add the shrink film as a seasonal inner pane. For the sealed crawlspace, fiberglass alone will still leak air, so cover it with a sealed rigid board or plywood panel, foamed around the edges. That stops the draft instead of just slowing it."

A third commenter said that while some people suggested replacing windows with glass block, that choice may not work well if the basement is meant to be used as living space. They noted that in their 1924 house, the nearly finished basement has glass block windows, and they wish the previous owners had not installed them because the windows can no longer be opened for fresh air on nice days.

When another century-home owner suggested rigid foam cut to fit snugly inside the frame, the original poster replied, "Really smart! Thanks, I think I'll go with this solve."

Where can I learn more?

Drafty windows and other air leaks can keep a home cold even after insulation is added. These stories cover a simple window test, air-sealing advice, and winter fixes for problem windows, skylights, and a window air conditioner.

• A two-minute paper test can help identify drafty windows before calling a heating professional.

• A first-time homeowner feeling cold coming through skylights received two inexpensive fixes from commenters.

• A Midwest homeowner unable to remove a garage window air conditioner received winter weatherization advice.