Garage Door Problem Guide
Garage Door Has a Gap at the Bottom
Daylight under the door lets in water, bugs, leaves and hot air. The fix depends on whether the gap is even, on one side, or new.
Quick answer
A gap under your garage door usually comes from a worn or flattened bottom seal, a close limit set too short, an uneven or sloped floor, or — if one side is higher — a cable or spring issue. Replacing the seal and adjusting the close limit fixes most even gaps; uneven gaps need a closer look.
Safety first: If the door is crooked or one side is clearly higher, don’t try to fix it by adjusting cables. That side may have a cable or spring problem.
Sort out the gap
Even gap all the way across
Likely the bottom seal is worn out or the close limit stops the door short.
Gap on one side only
The floor may slope, the seal may be worn on that side, or the door may be uneven because of a cable or spring.
Gap in the middle
The floor may have a dip, or the door’s bottom section may be bowed.
Safe checks you can do
- Close the door and look at the bottom seal — is it cracked, flattened, torn or missing in spots?
- Check whether the door is level by comparing panel lines with the opening.
- Watch the door close: does it stop before the seal touches the floor? That’s the close limit.
- Run a level or straightedge across the floor where the door lands.
Fixes
- Replace the bottom seal with the correct profile for your retainer.
- Adjust the close limit so the seal compresses lightly (then test auto-reverse).
- Add a threshold seal to the floor for a sloped or uneven slab.
- Repair cables or springs if the door is crooked.
Not comfortable checking this yourself?
Call and a technician can diagnose the door safely and explain the repair options.
What not to do
- Don’t crank the close limit so far that the door pushes into the floor and reverses.
- Don’t pile towels or sandbags against the door long-term; they trap moisture.
Related: weather seal replacement, opener safety & force adjustment, uneven on one side.
Repair Services for This Problem
When a basic check doesn’t solve it, these are the services that usually do.
Frequently Asked Questions
Why is there a gap under my garage door?
Most often a worn bottom seal, a close limit set short, or an uneven floor. A crooked door can also leave a gap on one side.
Can I replace the bottom seal myself?
Many homeowners can slide a new seal into an existing retainer. Make sure you buy the correct profile and width.
What is a threshold seal?
A rubber strip glued to the garage floor that the door closes onto, helpful for sloped or uneven floors.
Will adjusting the close limit fix the gap?
If the door stops short, yes. Test the auto-reverse afterwards.
Why is the gap only on one side?
Floor slope, a worn seal on that side, or a cable/spring issue making the door uneven.
Can a gap let snakes or rodents in?
Yes. Gaps under the door are a common entry point for pests. A good seal helps keep them out.
Still Having Trouble
With Your Garage Door?
Call to describe what the door is doing. We serve Augusta, Evans, Martinez, Grovetown, Hephzibah, North Augusta and Aiken.