Garage Door Letting in Cold Air and Drafts
A drafty garage door is almost always a worn or missing seal, not a broken door. Start by checking the bottom rubber seal, the seals along the sides and top, and whether the door sits flush against the frame when closed. In most homes you can fix it in an afternoon with a new bottom seal and weatherstripping for under $50, and you only need a pro if the door itself is warped, off-track, or won't close evenly.
Step by step
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1
Close the door and find where the cold is actually getting in
On a bright day, close the garage door and stand inside with the lights off. Look for daylight: a thin glowing line along the bottom, gaps at the two sides, or light at the top where the door meets the header. That glow is exactly where your cold air is coming in. Run your hand around the perimeter too, you'll feel the draft. Note every spot before you buy anything, because most drafty doors have two or three leaks, not just one.
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2
Replace the bottom rubber seal (the astragal)
The bottom seal is the #1 culprit, it cracks and flattens from sun, cold, and getting run over for years. Most doors have an aluminum retainer track on the bottom panel with a T-shaped or P-shaped rubber strip that slides in from the side. Measure your door's width and the seal's T-slot size, buy a matching replacement strip at any hardware store, spray the channel with a little soapy water, and slide the new seal through. If your door has no retainer track, a nail-on or screw-on bottom seal works too.
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3
Add or replace the side and top weatherstripping
The vertical jambs and the top of the doorway get a flexible vinyl weatherstrip (often called door stop weatherstrip) that has a flap pressing against the door's outer face. If yours is hardened, torn, or missing, pry off the old pieces, cut new strips to length with a utility knife, and nail or screw them so the flap just kisses the closed door, snug but not so tight it fights the door. This seals the side and top gaps you spotted in step one.
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4
Seal between the door panels with threshold or panel weatherstripping
On cold-climate doors, air sneaks in between the horizontal sections too. You can add thin self-adhesive foam or V-seal weatherstripping along the panel joints, or install a garage door threshold seal (a rubber strip that bonds to the floor itself) if your concrete is uneven and the bottom seal can't fully close the gap. The threshold is great for floors that slope or have low spots where the bottom seal leaves a wedge of daylight.
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5
Check that the door is closing all the way and sitting square
If you've replaced the seals and still feel a draft, watch the door close. It should land flat and even across the floor. If one corner hits first or there's a wedge-shaped gap, the door is out of level, a track is bent, or the opener's down-limit is set too high so the door stops short. Adjusting the opener's close limit can sometimes drop the door that last half inch onto the seal. If the gap is from the door itself being crooked, that's a pro fix (see below).
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6
Insulate the door if your garage is heated or attached
Sealing stops drafts; insulation stops the cold radiating through a thin steel door. If your garage is attached, finished, or you're trying to keep an adjacent room warm, add a garage door insulation kit (rigid foam panels or reflective batts cut to fit each section). It won't fix a draft on its own, but paired with good seals it makes a big difference in how cold the space feels and can quiet the door down too.
When to call a pro
Call a garage door pro if the door won't close flat against the floor, sits crooked or has an uneven gap across the bottom, drags or jumps in the tracks, or if you feel cold air pouring in around a door that looks closed all the way. Those point to a bent track, a worn or stretched cable, a sagging section, or a bottom panel that's no longer straight. Those are alignment and structural issues, not seal problems, and forcing the door or working near the spring system is where people get hurt, so it's worth a same-day service call before winter really sets in.
Call (888) 290-7421Frequently asked
Why is cold air coming in even though my garage door is fully closed?
The door panel itself is sealing the opening, but the gaps around the edges aren't. Air comes in under a worn bottom seal, along the side and top weatherstripping, between the horizontal panels, or through an uneven spot where the door meets the concrete. A closed door and a sealed door aren't the same thing, the rubber and vinyl around the perimeter are what actually block the draft, and those wear out long before the door does.
How much does it cost to fix a drafty garage door?
If it's just seals, it's a cheap DIY job. A new bottom seal runs about $15 to $30, side and top weatherstrip another $15 to $25, and a floor threshold seal around $40 to $70 if you need one. Most homeowners spend under $50 doing it themselves in an afternoon. If a pro replaces all the weatherstripping it's typically $75 to $200 with labor, and full door insulation kits add roughly $60 to $200 depending on door size.
Can I just use spray foam or caulk to stop the draft?
Caulk is fine for sealing the fixed gaps where the door frame meets the wall or the trim meets the brick, those don't move. But never foam or caulk the moving parts of the door or the gap the door closes into, you'll glue it shut or jam it. The bottom, sides, and top of the door opening need flexible rubber or vinyl weatherstripping that compresses when the door closes and springs back when it opens. Use the right seal for the moving edges and save the caulk for the stationary trim.
When should I just replace the whole door instead of resealing it?
Reseal first, it solves the draft for the vast majority of homeowners and costs a fraction of a new door. Consider replacement only if the door is visibly warped or rusted through, the panels are cracked or separating, it's a thin single-layer steel door and you want real insulation, or it's so old that seals no longer seat properly against bent sections. If the structure is sound, new weatherstripping and maybe an insulation kit will keep you warm without the four-figure price tag of a new door.
Rather leave it to a pro?
Licensed local techs, same-day service, upfront pricing, and a 1-year warranty.