6 Ways To Insulate Old Windows (When New Ones Aren’t in the Budget)

Stop us if this sounds familiar: Your thermostat is hiked up to 74 degrees, you’re covered in blankets, you’ve donned your fuzziest socks—and your house still feels cold.

The likely culprit: Drafty windows. Whether they’re old as dirt or just not energy-efficient, windows that let in cold air not only bring down your home’s temperature but also raise your heating bills because your furnace is working overtime.

First, take your windows’ temperature

Do you even have drafty windows? Before you get industrious by sealing cracks, you’ll want to figure out just how cold it is near the window. If you own one of the infrared thermometers we’ve become so familiar with during the coronavirus pandemic, you might be able to get a decent temperature reading and detect cold air leaking in from old windows.

“What these instruments do is capture what the eye cannot see, and that could be the radiant heat around the object,” says Matt Swann, a general contractor and president at Brawn Construction. “They can also help detect air leaks by measuring the ambient temperature in an area where cold air is leaking in.”

You can also look for visible cracks and gaps around the window frame, or try the old-school trick of shutting your window on a dollar bill. If you can pull the bill out easily, you have drafty windows.

If your bank account is a little lean these days, then replacement windows are probably out of the question. So you have two options: You could keep layering on socks and sweaters, or you could make your windows a lot more energy-efficient by trying these tips from the pros.

1. Caulk carefully

Caulking is good for sealing cracks, gaps, and joints less than a quarter of an inch. On the inside, keep bitter drafts out by caulking between the interior window trim and the wall. You can also apply caulk to the exterior perimeter of the window. Just be sure not to caulk weep holes, the small rectangular holes found on the bottom of the exterior side of the window frame.

“Caulking over weep holes is a big mistake,” warns Kevin Busch, vice president of operations at Mr. Handyman, a Neighborly Company. “Weep holes allow moisture to escape the window frame. Clogged weep holes can’t do their job properly, and your windows can rot, collect mold, or rust.”

Also avoid caulking the moving parts of the window and the ledge above the window frame, Busch says. Click here for complete instructions and tips for applying caulk.

Do note that the caulk aisle is massive. Be sure to read the labels, and buy caulk that is explicitly labeled for windows. Be sure to purchase exterior caulk for around the window outside, and interior caulk for inside. There are also caulks for humid spaces and masonry uses.

2. Weatherstrip for a temporary fix

When it comes to winter home maintenance, weatherstripping is a cheap and effective way to dodge bone-chilling drafts. Unlike caulk, which lasts around five years, weatherstripping is easy to apply and remove. It comes in a variety of…

Read More: 6 Ways To Insulate Old Windows (When New Ones Aren’t in the Budget)