Step-by-step fix
Step 1: Confirm the side weatherstrip is the problem
- Close the garage door fully from inside the garage.
- Look along both vertical sides for visible daylight, flattened rubber, torn vinyl, brittle edges, or sections pulling away from the jamb.
- Run your hand near the gap on a windy day to feel for drafts, but keep fingers clear of door joints and rollers.
- Check that the door itself is reasonably aligned. A badly racked or damaged door can create gaps that a new side seal will not fix.
- Measure the height of the opening and note how the current weatherstrip is mounted so you can buy the right style and length.
If it works: You have confirmed the side seal is worn or damaged and the mounting surface looks usable.
If it doesn’t: If the seal looks fine but the gap changes a lot from top to bottom, inspect the door tracks, rollers, and overall door alignment before replacing the weatherstrip.
Stop if:- The wood jamb is rotted, split, or loose.
- The door is visibly out of alignment or rubbing hard in the opening.
- You cannot safely reach the full height of the opening.
Step 2: Set up the area and remove the old weatherstrip
- Unplug any garage door opener or lock out wall controls so no one runs the door while you are working near the opening.
- Open the door if needed for access to the fasteners, then close it again before fitting the new strip so you can set the seal against the door face.
- Use a pry bar and hammer or a driver to remove the old weatherstrip and its fasteners from one side at a time.
- Pull remaining nails, screws, and broken seal material so the jamb face is flat and clean.
- Repeat on the other side if both side seals are being replaced.
If it works: The old side weatherstrip is off and the jamb surface is clear of old fasteners and debris.
If it doesn’t: If a few fasteners are stuck, work them out slowly instead of forcing the trim and damaging the jamb.
Stop if:- Removing the old strip exposes major rot, insect damage, or loose trim boards.
- The mounting surface breaks apart and will not hold new fasteners.
Step 3: Prep the jamb and cut the new weatherstrip
- Brush off dust and loose paint so the new strip can sit flat against the jamb.
- Measure each side from the floor to the top of the opening and transfer those measurements to the new weatherstrip.
- Cut the new pieces to length with a utility knife or other suitable cutter for the material.
- Dry-fit each piece in place before fastening to make sure the flange sits flat and the sealing edge reaches the door evenly.
If it works: The new weatherstrip is cut to size and fits the opening without forcing or buckling.
If it doesn’t: If the new strip seems too short, too stiff, or the sealing edge points the wrong way, recheck the style before fastening anything permanently.
Stop if:- The replacement profile clearly does not match the door and jamb setup.
- The new strip cannot sit flat on the mounting surface.
Step 4: Fasten the first side so it just contacts the closed door
- With the garage door fully closed, hold the first weatherstrip against the jamb so the flexible edge lightly presses against the door face.
- Start fastening near the top, then add a fastener near the bottom, keeping the strip straight as you go.
- Work down the length with evenly spaced fasteners, checking often that the seal is touching the door without being crushed flat.
- Adjust the strip slightly in or out as needed before fully tightening or setting all fasteners.
- Trim any excess at the bottom so the strip ends neatly near the floor without curling into the door path.
If it works: The first side is straight, secure, and makes light, even contact with the closed door.
If it doesn’t: If the door binds when opened by hand, back the strip off slightly so the seal is snug but not pinched hard.
Stop if:- The jamb will not hold fasteners securely.
- The door catches hard enough that it strains, twists, or will not move freely by hand.
Step 5: Install the second side and fine-tune the seal
- Repeat the same process on the other side with the door closed.
- Compare both sides from inside the garage and look for an even seal line from top to bottom.
- Open and close the door by hand to make sure the weatherstrip does not fold under, snag, or drag excessively.
- Make small adjustments where you still see light or where the seal presses too hard.
If it works: Both side weatherstrips are installed and the door moves normally while the side gaps are sealed.
If it doesn’t: If one area still shows a gap, loosen that section and shift the strip slightly toward the door, then retest.
Stop if:- A large gap remains because the door is warped or out of alignment.
- The top corner or bottom corner gap cannot be corrected with weatherstrip position alone.
Step 6: Test the repair in real use
- Reconnect the opener or restore normal controls if you disconnected them.
- Run the door through a full open-and-close cycle and watch the side seals as the door returns to the closed position.
- From inside the garage, check for daylight along both sides and look at the bottom corners where leaks often show up first.
- If possible, hose the exterior lightly or wait for the next rain and inspect for water getting past the side edges.
- Recheck fasteners after a day or two if the new material settles slightly.
If it works: The door closes normally, the side gaps are sealed, and drafts or water intrusion at the sides are reduced or gone.
If it doesn’t: If water still gets in at the corners, inspect the bottom seal, threshold, and door alignment along with the new side weatherstrip.
Stop if:- The opener struggles or reverses because the door is binding.
- Water is entering through damaged trim, wall joints, or other areas outside the side seal repair.
Replacement Parts
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FAQ
Should the side weatherstrip press tightly against the door?
It should make light, even contact. Too loose leaves gaps, but too tight can make the door bind or wear the seal out faster.
Can I replace just one side?
Yes, if only one side is damaged. If both sides are brittle or flattened, replacing both at the same time usually gives a more even seal.
Why do I still have a gap after installing new weatherstrip?
The door may be out of alignment, warped, or the wrong weatherstrip profile may have been used. Corner leaks can also come from a worn bottom seal or an uneven floor.
Do I need to remove the garage door to do this repair?
No. Side weatherstrip is normally replaced from the jamb side with the door in place.
What if the wood behind the old weatherstrip is rotten?
Fix the damaged wood first. New weatherstrip will not stay secure or seal properly if the mounting surface is soft, split, or loose.