Feel a cold breeze near the front door in winter? That draft is costing you money. Gaps around exterior doors let heated and cooled air escape all year. Learning how to weatherstrip a door is a cheap, quick project that makes your home more comfortable and can help lower energy bills.
How to Find Air Leaks Around a Door
On a windy day, hold a lit incense stick or a damp hand near the edges of the closed door. If the smoke wavers or you feel air, you’ve found a leak. At night, you can also have someone shine a flashlight from outside while you look for light around the frame.
Check three areas: the top and sides of the frame, and the gap at the bottom of the door.
Types of Door Weatherstripping
Adhesive foam tape: Cheapest and easiest. Good for small, even gaps, but it wears out in a year or two.
V-strip (tension seal): A folded strip of vinyl or metal that springs open to fill gaps along the sides of the door. Durable and nearly invisible.
Compression or kerf-in seals: Rubber or silicone seals that press into a slot in the door frame. They’re a common factory style and are easy to replace.
Door sweeps: Strips of rubber, vinyl or brush that attach to the bottom of the door to seal the gap above the threshold.
Tools and Materials
- Weatherstripping sized for your door
- Door sweep
- Tape measure and utility knife or tin snips
- Screwdriver or drill
- Rubbing alcohol and a clean rag
Step 1: Remove Old Weatherstripping and Clean
Pull off old, flattened or cracked strips. For kerf-in seals, grab the end and pull it straight out of the slot. Scrape away leftover adhesive, then wipe the frame with rubbing alcohol. Adhesive sticks best to a clean, dry surface above about 50°F.
Step 2: Measure and Cut
Measure the top of the frame and each side separately. Cut the weatherstripping to length, erring slightly long. You can always trim more, but you can’t add it back.
Step 3: Install Weatherstripping on the Frame
Start with the top piece, then do the sides. Press adhesive strips firmly along the door stop where the door closes against the frame. For kerf-in seals, push the flange into the slot with your thumb or a putty knife.
Test the Door
Close the door. It should shut and latch without heavy force. If it’s too tight, switch to a thinner seal. If it won’t latch at all, our guide on fixing a door that won’t latch can help with strike plate adjustments.
Step 4: Install a Door Sweep
Measure the door width and cut the sweep to fit. Close the door and hold the sweep against the inside face so the rubber lightly touches the threshold. Mark the screw holes, drill small pilot holes and fasten it. The door should open without dragging.
Don’t Forget Windows
Windows leak air too, especially older ones. The same V-strip and foam tape work on the sashes of double-hung windows. For gaps between the window trim and the wall, a bead of paintable caulk seals things up. Fixed windows that never open can simply be caulked around the inside trim.
Check Your Seals Every Year
Weatherstripping compresses and cracks over time. Check your seals each fall before heating season, and replace any that are torn or flat.
More Ways to Keep Your Home Efficient
Door seals are just one item on our seasonal home maintenance checklist. Next, learn how to clean a dryer vent to improve efficiency and safety. Replacing a worn threshold during a floor upgrade? Our laminate flooring guide covers trim and transitions. A squeaky front door? Here’s how to fix a squeaky door in 15 minutes.
