Symptom check
Leaves, mice and cold air are getting in around the garage door
An even gap under a closed garage door is usually a worn bottom seal, a quick replacement. A gap wider at one end means a settled slab, a slack lift cable or a door out of level, which needs a look before any seal.
Updated
See what shape the gap is
Close the door, switch off the overhead light, and look along the bottom edge and up the sides for daylight. An even strip is a seal problem; a wedge points at the slab, a cable or the way the door hangs. If one bottom corner sits higher and a cable looks slack, leave the door closed and call rather than running it.
What usually causes it, in order
The shape of the light around the closed door sorts these causes faster than any tape measure.
- Most common
A worn, flattened or torn bottom seal
What you notice: Light shows evenly along the bottom, and the rubber strip is flat, cracked, split or missing in places.
The repair: Replace the bottom seal, and the retainer channel it slides into if that has rusted or bent. Garage Door Weather Seal Replacement, from $145
- Common
A slab that has settled or sloped
What you notice: The seal is soft and whole, but the gap opens toward one end where the concrete dips, most often in an older garage.
The repair: Fit a taller bottom seal, or a slab-mounted threshold, to close a low spot a standard seal cannot reach. Garage Door Weather Seal Replacement, from $145
- Common
Worn side and top weatherstrip
What you notice: Daylight runs up a side or along the header, and the flexible flap on the jamb trim has curled, cracked or pulled away.
The repair: Replace the weatherstrip on the jamb trim and header so it lightly touches the closed door. Garage Door Weather Seal Replacement, from $145
- Less common
A lift cable stretched or slipping on its drum
What you notice: The gap is a clean wedge, one bottom corner sits higher, and one cable looks looser than the other.
The repair: Replace both lift cables and set them evenly on the drums so the door hangs level again. Garage Door Cable Replacement, from $185
- Less common
A track or jamb out of plumb
What you notice: The door stands away from the side seal on one edge, a vertical track leans, or the door rubs at the top as it closes.
The repair: Realign and refasten the tracks and brackets, then set the perimeter seal to the corrected door. Garage Door Track Repair, from $165
Safe checks before you call
Do these on a bright day from inside a dark garage, so daylight does the measuring for you.
- Look along the bottom edge for an even strip of light, a wedge, or light at one corner only.
- Press the bottom seal with a finger at several points to feel whether it is soft or stiff and cracked.
- Check the side and top trim for a flexible flap that has curled away from the door.
- Compare the two lift cables at the bottom corners by eye; one hanging slack is a reason to stop and call.
- Look for droppings, chewed rubber or nesting scraps near the corners, which show where pests come in.
A wedge of light means the door, not the seal
If the gap is wider at one end, a new seal will not cure it, because the door itself, its cables or the slab are out of level.
Each lift cable climbs from a bottom bracket to a drum on the spring shaft, and the two must carry the same share of the door. A cable that has stretched, frayed or slipped a wrap on its drum lets one corner ride high, and a thicker seal only hides that until the cable lets go.
Those cables and brackets are under spring tension the whole time the door is closed, so leave them alone and text a picture of both bottom corners instead.
How the age of a Clark County garage shapes the gap
Around Clark County the gap tends to track how old the house is: worn original seals on the newer tracts, settled slabs and tired trim on the old detached garages.
More than half of all housing units in the county date from 1990 or later, so plenty of garages may still carry the bottom seal the builder fitted, and rubber that has spent twenty or thirty winters in the rain goes flat and hard. A new seal and fresh side weatherstrip usually close those doors up for good.
The detached alley garages behind houses built from the 1910s to about 1940 in Hough and Shumway, and the older stock in Kelso and Longview, can sit on slabs that have settled over the decades. There we fit a taller seal or a threshold strip rather than chase the concrete.
Keeping mice and rats out at the corners
Rodents get in at the low corners where the seal has split or the slab dips, and a long wet winter sends them looking for dry space.
Rubber is easy to chew once there is an edge to start on. Where pests are the problem we fit a fresh seal with tight ends, close the corner where the side weatherstrip meets the floor, and point out any opening in the wall or slab that is not part of the door.
Gap under or beside the door: questions and answers
How do I tell if the gap under my garage door is the seal, the slab or a cable?
Look at the shape of the light with the door closed. An even strip means the seal has worn. A gap that follows a dip in the concrete is the slab. A clean wedge with one corner higher and one cable looser points to the cable, which is a repair call.
Why is there light at the sides of my closed garage door?
Light along the sides comes from a worn perimeter seal on the jamb trim, or from a track that has drifted away from the jamb. That seal curls, cracks and shrinks with age. A new perimeter seal set to lightly touch the closed door fixes the first. A leaning track needs realigning before the seal goes on.
Why is the gap under my garage door bigger on one side?
An uneven gap means one end of the door, or the floor under it, sits lower. A settled slab is a common reason in older garages, and a stretched or slipping lift cable is the other. If a cable looks slack or a corner sits high, stop using the door and call.
Can a new bottom seal close the gap under my garage door if the floor is uneven?
Usually, within limits. Bottom seals come in several heights and profiles, and a taller bulb, or a threshold under the door, can fill a shallow dip in the concrete. A dip deeper than any seal can follow is concrete work, and we will say so plainly.
How do mice get in through the gap under a garage door?
Through the corners, where a split seal, a torn end or a dip in the slab leaves an opening a mouse can squeeze through. Once rubber has an edge, rodents chew it wider. A fresh seal with tight ends, plus a corner seal where the jamb meets the floor, closes the usual entry points.
Where to go next
Nearby service areas
This call comes in from Hudson's Bay and Columbia Way, Marrion, Ridgefield and the rest of our Washington service area.
Want a price before anyone drives over?
Call and describe what the door is doing, or text a photo of the door and the spring above it. You hear the likely repair and where its price starts, then decide.