How to Weatherstrip the Sides and Top of Your Garage Door
To weatherstrip the sides and top of your garage door, you'll install vinyl or rubber "garage door stop" weatherseal along the wood door jambs and header. Close the door, snug the flexible flap against the face of the door, and nail or screw the rigid backing strip to the jamb every 12 to 16 inches. The whole job takes about an hour and runs $25 to $50 in materials for a standard single-car door.
Step by step
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1
Measure your door and buy the right weatherseal
Measure both vertical jambs (the sides) plus the header (the top) and add them up. A standard 7-foot-tall, single-car door needs roughly 7 + 7 + 9 = about 23 feet, so buy a 30-foot roll to give yourself margin. Get vinyl or rubber 'garage door stop molding,' which has a rigid flat nailing strip and a flexible flap on one edge. Pick white, brown, or almond to match your trim. If your existing wood stop is rotted or your door has no stop at all, buy the version with the wood backing; if the wood is solid, buy the flap-only replacement seal.
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2
Remove the old weatherstripping and clean the surface
Pry off the old vinyl or rubber stop with a flat pry bar, pulling out the old nails as you go. Scrape off any crumbled foam, caulk, or debris, and wipe the jamb down so you're fastening to clean, dry wood. While you're there, check the wood jamb for rot or soft spots, press on it with a screwdriver. If it crumbles, replace that section of jamb before you weatherstrip, or the new seal won't hold.
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3
Close the door and start at the bottom of one side
Close the garage door fully so you can set the seal against the real door position, this is the single most important step for a tight result. Start at the bottom of one vertical jamb. Hold the new stop so the flexible flap just barely touches the face of the door panel, light contact, not crushed flat. Too loose and you'll see daylight; too tight and the door binds or wears the seal out fast.
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4
Fasten the side strips, working bottom to top
With the flap kissing the door, drive a galvanized or stainless nail (or exterior screw) through the rigid backing every 12 to 16 inches. Galvanized resists rust in a humid garage. Keep checking the flap contact as you go up, the door isn't always perfectly plumb, so you may need to ease the seal in or out slightly to follow it. Repeat on the second side.
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5
Do the top header last and miter the corners
Cut the top piece to span the header and butt it against the two side pieces. For a clean, leak-free corner, cut the ends at a 45-degree miter so the side and top flaps meet without a gap, the corners are where wind and water sneak in. Fasten the same way, every 12 to 16 inches, with the flap touching the top of the door.
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6
Test the seal and seal the gaps
From inside the closed garage in daylight (lights off), look around the door's sides and top for any slivers of light, that's where air and water still get through. Adjust those spots by re-snugging the flap or adding a fastener. Finish by running a bead of exterior paintable caulk along the back of the wood stop where it meets the jamb to block the last drafts and keep water out of the wood.
When to call a pro
Call a pro if the wood jambs or header are rotted and need replacing, if the door itself is bent or out of alignment so no seal can close the gap, or if you'd rather not deal with a ladder and miter cuts, most garage door companies will weatherstrip a door in well under an hour.
Call (888) 290-7421Frequently asked
What's the difference between the side/top seal and the bottom seal?
They're two different products. The sides and top use a 'stop molding' weatherseal, a rigid strip that nails to the wood jamb with a flexible flap pressing against the face of the door. The bottom uses an 'astragal' or T-shaped/bulb seal that slides into a track on the bottom edge of the door itself and compresses against the floor. Don't try to use one in place of the other.
How do I know when my garage door weatherstripping needs replacing?
Look for daylight around the closed door from inside, cracked or hardened vinyl that no longer flexes, flaps that are torn or curling away from the door, or water and leaves blowing in during storms. A quick test: close the door and slide a dollar bill along the seal, if it slips through anywhere without resistance, that section has lost its seal. Most vinyl side and top seals last 5 to 10 years before sun and cold harden them.
Will weatherstripping my garage door actually lower my energy bills?
If your garage is attached or you've got finished space above or beside it, yes, sealing the sides and top stops drafts that make your HVAC work harder, and it helps keep the adjoining rooms more comfortable. For a detached, unheated garage the savings are smaller, but you'll still keep out rain, snow, dust, leaves, and pests, which is reason enough for a $30 roll of seal.
Do I have to remove the old wood stop molding, or can I seal over it?
If the existing wood stop is solid and straight, you don't have to remove it, you can buy flap-only replacement weatherseal that nails right onto the face of the wood stop. Only remove the wood when it's rotted, split, or warped. If your door has no stop molding at all, buy the all-in-one vinyl stop with the integrated backing and install it directly to the jamb.
Rather leave it to a pro?
Licensed local techs, same-day service, upfront pricing, and a 1-year warranty.