Weatherstripping is the thin seal around your doors and windows that keeps outside air out and conditioned air in. It's inexpensive, it wears out quietly over the years, and checking it is one of the fastest ways to cut down on drafts before the weather turns. Drafts from worn seals can account for 10 to 20 percent of a home's heating and cooling costs, so this is a small job with a real payoff.
How to check it
A few simple tests will tell you where you stand:
- The paper test. Close a door or window on a strip of paper and try to pull it out. If it slides out easily with little resistance, the seal is too loose.
- The hand test. Run your hand slowly around the edges of a closed door or window on a windy or cold day. Cold air moving across your skin means a gap.
- The light test. At night with the lights on inside, have someone check from outside for light escaping around the frame.
- Look and listen. Visible gaps, cracked or brittle material, and windows that rattle when closed are all signs it's time to replace the seal.
Early fall, before you're relying on the furnace every day, is the best time to run through this check.
Types of weatherstripping
- Foam tape. Inexpensive and easy to install, works well for irregular gaps, though it wears out faster than other options.
- V-strip (tension seal). A durable, low-profile option that works well on double-hung and sliding windows.
- Spring metal. Long-lasting and largely invisible once installed, a good fit for wood windows.
- Tubular vinyl. Handles larger gaps well, though it's more visible than other types.
- Door sweeps. A separate strip that attaches to the bottom of a door to seal the gap above the threshold.
How to replace it
- Peel or gently pry off the old weatherstripping. A putty knife helps with anything stuck on with old adhesive.
- Clean the frame thoroughly and let it dry completely so the new material can adhere properly.
- Measure the gap and cut the new material to length.
- Press adhesive-backed strips firmly into place, or nail or screw in strips that require it, following the product's instructions.
- Close the door or window and check for drafts and smooth operation. It should seal snugly without binding.
Most doors and windows only need a putty knife, scissors, and a screwdriver to handle. Materials typically run $10 to $40 per door, which is a small cost against a noticeably drafty room.
When it's more than weatherstripping
If you've replaced the seal and you're still feeling drafts, the issue may be the door or window itself: a warped frame, a cracked pane, or settling that's thrown the unit out of square. That's worth a call to a contractor rather than another roll of foam tape.
This is a quick one to add to your fall maintenance list alongside checking the furnace filter and scheduling your HVAC tune-up.
