How to Replace the Side and Top Weatherstripping on a Garage Door
To replace the side and top weatherstripping on a garage door, pry off the old vinyl or rubber stop molding from the jambs and header, measure each side and the top, then nail or screw new weatherstrip molding into place with the flexible flap pressing lightly against the closed door. It's a straightforward one-to-two hour DIY job that usually costs $25 to $60 in materials and needs only a pry bar, a hammer or drill, a utility knife, and a tape measure. Keep the door closed while you install so the new flap seals snug without binding.
Step by step
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1
Gather materials and measure your door
You'll need new garage door weatherstrip molding (sold in kits or by the foot at any home center), a pry bar, a hammer with galvanized nails or a drill with exterior screws, a utility knife, a tape measure, and a caulk gun. Measure the two vertical sides and the horizontal top of your door opening, then add about 6 inches to your total so you have room to trim. Most single doors need roughly 24 feet; a double door needs around 30. Buy molding rated for exterior use so it won't crack in the sun or stiffen in the cold.
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2
Remove the old weatherstripping
Slide your pry bar behind the old stop molding and gently work along its length, pulling the wood or vinyl strip away from the jamb and header. Go slow so you don't gouge the door frame. Pull out any leftover nails or screws with pliers and scrape off old caulk and debris. Wipe the surface clean and let it dry. If the wood jamb underneath is rotted or soft, patch or replace it before you go any further, or the new seal won't hold.
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3
Cut the top piece and miter the corners
Hold a length of new molding across the top of the opening and mark your cut. For the cleanest seal, cut the ends at a 45-degree angle so the top piece and the side pieces meet in a tight miter at each corner, like a picture frame. A miter box helps, but a careful utility-knife or hacksaw cut works on vinyl molding. Dry-fit the top piece first to confirm the angle before you fasten anything.
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4
Install the top piece with the door closed
Close the garage door first, this is the step people skip, and it's the one that makes or breaks the seal. With the door down, press the top molding into place so the flexible flap just kisses the outside face of the door, snug but not crushed. Too tight and the door strains or won't latch; too loose and you'll still feel a draft. Fasten every 12 to 16 inches with galvanized nails or exterior screws.
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5
Install the two side pieces
Cut each side piece to length with a matching 45-degree miter at the top so it nests against the top piece. Keep the door closed, hold each strip so the flap presses lightly against the door, and work from top to bottom. Check that the flap contacts the door evenly along its whole height before you nail, gaps usually mean the molding isn't parallel to the door. Fasten every 12 to 16 inches on both sides.
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6
Seal, test, and clean up
Run a bead of exterior-grade caulk along the back edge where the molding meets the jamb to block wind and water. Open and close the door a few times to make sure it runs smoothly and the new seal isn't binding or pulling. With the door closed, do the daylight test: stand inside on a sunny day and look for light leaking around the edges. No light means a good seal. Adjust any spot that gaps, then you're done.
When to call a pro
Call a pro if the wood jamb is rotted and needs rebuilding, if the door binds or won't latch after the new seal goes on, or if you'd rather not work around the door's spring and track hardware, our technicians can swap all the seals and check the door's balance in one quick visit.
Call (888) 290-7421Frequently asked
What's the difference between the side weatherstripping and the bottom seal?
They're two different parts. The side and top weatherstripping is the molding that mounts to the door frame (the jambs and header) and seals the gap around the perimeter of a closed door. The bottom seal is a separate U-shaped or beaded gasket that slides into a track on the bottom edge of the door itself. Replacing one doesn't replace the other, so if you feel drafts all around, plan to do both.
How often should garage door weatherstripping be replaced?
Most side and top weatherstripping lasts five to ten years, but sun, freezing temperatures, and everyday wear shorten that. Replace it when you see cracking, brittleness, or gaps, when daylight shows around the closed door, or when you notice drafts, water, leaves, or pests getting in. A quick visual check each spring and fall will catch problems early.
Can I use any weatherstripping, or do I need a special garage door kit?
Use weatherstripping made for garage doors. It comes as a one-piece molding with the wood or vinyl mounting strip and the flexible flap already attached, sized for the gap around a garage door. Generic door or window foam tape won't hold up to the weather or the door's movement. Garage door kits are inexpensive and cut to the right profile, so they're worth it.
Should the door be open or closed when I install the new weatherstripping?
Closed. Installing with the door shut lets you press the flap so it just touches the outside face of the door, which is exactly the contact you want for a tight seal. If you install with the door open and guess at the position, the flap usually ends up too tight (the door strains or won't latch) or too loose (you still get drafts).
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