What causes a gap under a garage door?

A gap under a garage door can come from the bottom seal, the floor, the door position or a movement problem. Note the shape and location of the gap before assuming a thicker seal will correct it.

Describe the gap while the door is at rest

Is the gap even across the opening, limited to one corner or broken into several small areas? Does the bottom edge appear level within the frame? Report what you see without reaching under the door or putting fingers between sections. Mention whether the gap is new, followed an impact or has existed since installation. A safe photograph of the closed opening can help distinguish the contact pattern without encouraging repeated operation.

Separate seal wear from uneven seating

A split, hardened or missing seal can reduce contact, but an otherwise intact seal may not compensate for an uneven floor or abnormal door position. If the door tilts, binds or has a displaced cable, keep it unused and seek assessment rather than treating it as a weather-stripping issue. Do not change opener force to press one side down. The door must continue to travel and reverse as intended by its manufacturer.

Match the replacement profile

Bottom retainers and seals come in different arrangements. Ask which compatible profile, dimensions and material are proposed for the actual assembly and whether the retainer needs repair. A generic strip chosen only by opening width may not fit. Perimeter trim, thresholds and bottom seals address different conditions. Discuss any effect on drainage, clearance and normal operation before adding a threshold or another layer beneath the door.

Clarify the intended result

Ask whether the proposal is expected to reduce visible light, debris entry or a specific contact gap. Do not assume it creates an airtight or waterproof opening. Standing water, driveway slope and wind-driven rain can require separate evaluation. If the gap is caused partly by the floor, ask what a seal can reasonably accommodate and what remains outside the door repair scope. A clear limitation is more useful than an absolute weatherproofing promise.

Prepare a focused request

Share the city, gap location, whether the door is level and any associated noise or travel change. Include model details only if safely accessible. Ask I-95 Garage Door whether the requested seal or door assessment is supported. Request the parts, retainer work and operating checks included in the estimate, and keep the installed seal information and care instructions. The right next step follows the cause of the gap, not its appearance alone.

For model-specific operating and troubleshooting information, use your manufacturer’s manual. See LiftMaster’s service guidance and Clopay’s repair information.