A strip of daylight beneath your garage door does not always mean you need a new door. It may point to a worn bottom seal, damaged perimeter weatherstripping, or a gap between the door and the concrete. The right repair depends on where the gap is and whether the door closes evenly.
For homeowners in Denver and Lakewood, the useful first step is to identify the location of the opening. That makes a service request more specific and helps distinguish a seal problem from a door that needs mechanical inspection.
Bottom seal, perimeter seal or floor gap?
| Where you see the gap | What to inspect | Important distinction |
|---|---|---|
| Along the bottom edge | Bottom seal and retainer | The replacement must fit the door's attachment profile. |
| At the sides or top | Perimeter weatherstripping | Contact with the closed door should be evaluated. |
| In one area of the floor | Floor slope, drainage and door position | A larger seal may not solve the underlying gap. |
The bottom seal is the flexible material along the lower edge of the door. It may fit into a metal retainer or attach through another manufacturer-specific system. A replacement must match the mounting method and door, not just the apparent width of the old rubber.
Perimeter weatherstripping sits around the sides and top of the opening. Its flexible edge contacts the closed door. Tears, loose trim or uneven contact can leave gaps even when the bottom seal is intact.
A low spot or slope in the floor is a different problem. A larger seal may not solve it, and a threshold changes the surface beneath the opening. Before choosing a threshold, discuss drainage, vehicle clearance and how the door will contact it. A seal is not a substitute for correcting an unsafe or crooked door.
What you can observe safely
With the door closed, look from inside the garage for daylight at the bottom, sides and corners. Photograph the gaps and note whether the lower edge appears level. Look for torn material, loose perimeter trim or a section of seal that has pulled out of its retainer.
If water enters, note where it travels during wet conditions. Water flowing toward the opening can require drainage work in addition to a seal. Do not assume new rubber will make a garage waterproof.
Questions to ask before replacement
Ask which component is being replaced and why. An estimate should distinguish the bottom seal from its retainer, side-and-top trim, and any proposed threshold. Ask whether the existing retainer is reusable and whether the replacement is compatible with your specific door.
A useful estimate identifies the gap and the proposed repair
- Which seal or retainer needs replacement?
- Is the proposed material compatible with this door?
- Does the door close evenly without binding?
- Does water drainage need separate attention?
The technician should also consider whether the door reaches its normal closed position without binding. Increasing opener closing force to compress a seal is not an appropriate substitute for finding the cause of poor closure. Follow the opener's exact owner manual for adjustments and safety testing.
Seasonal checks for a Denver-area garage
Check the seal before winter and after visible damage. Keep the doorway free of accumulated debris and watch for water collecting at the bottom edge. If the seal appears frozen to the ground, do not repeatedly run the opener to pull it loose. Stop and assess the obstruction before attempting normal operation.
Denver's local temperature and snowfall records are available from the National Weather Service. Those records provide regional context, but an individual garage's exposure, drainage and door condition determine what needs attention.
Frequently asked questions
Will a new seal stop every draft?
It can address the gap it is designed to cover. Air may still enter through panel joints, perimeter gaps or other parts of the garage. Check the whole opening before expecting one strip of rubber to solve every draft.
Can I order a seal using the door width alone?
Width is only one measurement. The retainer profile, attachment style and door compatibility also matter. Photograph the door label and existing seal for a more useful discussion with a professional.
Does a floor gap mean the door should close farther?
Not necessarily. Floor slope, seal damage or an uneven door can look similar. Have the cause identified rather than changing travel or force settings to push the door down harder.
Ask Bolt about the gap you see
Tell us your city, door type and where you see daylight or damaged material. A photo of the closed door and seal can help explain the issue before an inspection.
Call 720-500-7199More help for your garage door
Explore our Colorado maintenance checklist or find your community in the Denver metro service-area directory.