A gap under a garage door is not always just a worn rubber seal. In Connecticut homes, uneven concrete, settled slabs, sloped driveways, old wood jambs, rusted bottom sections, and out-of-square doors can all leave daylight under the door. The right fix depends on whether the door is closing correctly before you try to seal it.

Start by identifying the type of gap

A straight gap across the whole bottom often points to a worn or undersized bottom seal. A gap on one corner can point to uneven concrete, a crooked door, track alignment, cable tension, hinge wear, or a door that is not sitting level. A gap that appears only after opener adjustment may point to travel limits or closing force.

FAQ

Why is there a gap under my garage door?

Common causes include a worn bottom seal, uneven concrete, a settled slab, a crooked door, track or limit adjustment issues, or a door that is not closing squarely.

Will a bigger bottom seal fix an uneven concrete floor?

Sometimes, but not always. A larger seal can help smaller gaps, while bigger uneven-floor problems may need a threshold, adjustment, concrete work, or door repair.

Should I add a threshold seal to the garage floor?

A threshold can help stop water and drafts, but it must be placed correctly so it does not trap water in the wrong direction or interfere with door travel.

When is a bottom gap a repair problem instead of a seal problem?

If the door is crooked, heavy, off track, hitting one side, or leaving a gap on only one corner, the hardware should be inspected before just replacing rubber.