Ants, cockroaches and other pests use gaps around a garage door. A worn bottom seal, an uneven floor or a torn side seal can let them in. Find the gap by looking for daylight along the edges, replace a flattened or cracked seal, and seal other cracks around the garage. A seal helps keep pests out, but it does not remove an infestation.
Why pests use the garage
A garage is a cool, shaded space, often with stored boxes, pet food or trash cans, and a big door that does not seal as tightly as a front door. Texas A&M AgriLife Extension says ants can become indoor pests when they enter residences in search of water, and that cockroaches looking for the right temperature and water can lead them inside.
AgriLife also says the way to keep these pests outdoors is exclusion, meaning you seal the ways in. For a garage, that starts at the bottom edge of the door.
How the door lets them in
A garage door rides on rollers and has a rubber or vinyl seal along the bottom, with vinyl stops down the sides and across the top. Pests do not need a big opening. An AgriLife specialist notes that rodents only need 1/4 inch, about the size of a dime, to start to make entry into a home.
The usual weak spots are a bottom seal that is flattened, cracked or torn, a floor that dips so the seal does not meet it, a side seal that has pulled away, and gaps at the corners of the door.
Find the gap in ten minutes
- Close the door and turn off the garage lights. Have someone outside with a flashlight, or wait for daylight, and look along the bottom for light showing through.
- Check the corners, where the bottom seal meets the side seals.
- Look at the seal itself: is it flat, split, hard or missing a piece?
- Run a hand along the side and top stops for loose spots.
- Look around the garage for cracks in the slab and gaps around pipes and wires.
What the fix looks like
If the seal is worn, replacing it is a normal repair that does not involve the springs. See bottom seal replacement and side and top weatherstripping. A technician can also tell you whether the door is hanging evenly, because a sagging door can leave a gap that no seal will close.
If the floor dips, a thicker seal or a threshold seal may fill it. Texas A&M's urban entomology program also advises sealing any cracks of 1/8 inch or more in the foundation and exterior walls and keeping thresholds as tight as possible, which applies to the garage walls and the door between the garage and the house.
Other things to seal
AgriLife entomologists say to replace weather-stripping around doors and windows as necessary and to seal cracks, crevices and pipe penetrations in exterior walls with sealant. In the garage, that means the door into the house, the pipe and wire openings, and the cracks along the slab.
A new seal blocks one way in. If you already see ants or roaches indoors, keep food and water sources out of the garage and talk to a pest control professional about treatment. Seals and treatment work together.
When to call us
Call if the bottom seal is torn, the door leaves a gap you cannot close, or the door sits uneven. See garage door repair and parts. Never adjust a spring or cable to level a door; that is a job for a technician. A quote should name the seal, the length and the labor.
Emil Garage Doors repairs garage doors, springs, cables and openers and installs new doors in Texas, including Sugar Land, Conroe and League City. Call or send your details with a photo of the gap.
Questions people ask
Why do ants come into my garage?
Texas A&M AgriLife Extension says ants can become indoor pests when they enter residences in search of water. A gap at the garage door or a crack in the slab gives them a way in.
Will a new bottom seal keep roaches out?
It closes one common entry point, and AgriLife says exclusion is the way to keep these pests outdoors. It does not remove roaches already inside, so combine it with sealing other cracks and pest control.
How big does a gap have to be?
Smaller than most people think. AgriLife notes that rodents need only 1/4 inch, about the size of a dime, and Texas A&M advises sealing cracks of 1/8 inch or more in foundations and exterior walls.
Can I replace the bottom seal myself?
Many homeowners do, but if the door is crooked, heavy or hard to lift, stop and call a technician. Never adjust a spring or cable to level the door.
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