Bottom seals · perimeter stops · thresholds
Garage Door Weather Seal Replacement
If you can see daylight under the closed door, or water runs into the garage every time it rains, the weather seal has failed. It is one of the least expensive garage door repairs and one of the most useful.
Sounds like this if
- Light shows under or around the edges of the closed door
- Rain or snowmelt runs in under the door
- Leaves, dust or mice get into the garage
- The rubber at the bottom is cracked, flattened or torn
Free to call · answered 24/7
The three seals on a garage door
Bottom seal
A rubber or vinyl strip that slides into a retainer along the bottom edge of the door. It squashes against the floor when the door closes. Most are a U-shape, a bulb or a T-shape, and the shape has to match the retainer channel on your door. This is the seal that wears out first.
Perimeter stop (side and top seal)
A flexible flap on a wood or PVC strip nailed around the outside of the opening. It presses against the face of the door when it is closed. Over time it dries out, cracks and pulls away, especially on the sunny side.
Threshold
A raised rubber strip glued to the garage floor under the door. It is useful where the floor slopes toward the garage or has settled and left a gap that a bottom seal alone cannot close.
Choosing the right bottom seal
| Seal shape | Best for | Notes |
|---|---|---|
| T-style (bead) seal | Most steel doors with a single or double channel | The beads must match the retainer channel width |
| Bulb seal | Doors with a slightly uneven floor | The rounded bulb flattens to fill small dips |
| J-type or nail-on seal | Wood doors without a retainer | Nailed or screwed to the bottom of the door |
| Thick or tall bulb | Larger gaps, sloped driveways | May need the opener close limit adjusted |
| Brush seal | Commercial and roll-up doors, uneven surfaces | Lets some air through but blocks debris and pests |
Side, top and section seals
The perimeter stop around the opening comes in wood, vinyl and PVC with a soft flap or bulb. PVC does not rot and holds up better near salt water, and it is a common upgrade when old wood stop molding has split. It should be set so the flap just touches the closed door: pressed too tight, it drags on the door and makes the opener work harder.
Many insulated doors also have a seal built into the joint between sections, so the joints close tight when the door is down. On an older door without one, drafts through the joints are normal and cannot easily be fixed without a new door.
Why seals fail faster in New York
Seals take a beating from both seasons. In summer, direct sun on a south- or west-facing door dries out rubber and vinyl. In winter, the bottom seal can freeze to the floor, and when the opener lifts the door it tears. Road salt dripping off cars makes rubber harden, and on Long Island's coast, salt air and sand do the same.
Upstate, where snow piles up against garage doors for months, a seal that does not close tightly lets meltwater run in and refreeze, which can lock the door to the floor and buckle the bottom section over time. Our winter guide explains how to free a frozen door without damage.
What a seal replacement involves
Identify the retainer
The technician checks the channel on the bottom of the door: single or double track, the width, and whether it is aluminum or steel. If the retainer is bent or rusted, it is replaced too.
Slide out the old seal
The door is raised to a working height and locked in place. The old seal is pulled out of the channel, which is cleaned.
Fit and trim the new seal
A new seal is slid in and trimmed to the door width, with the ends crimped so it stays put.
Check the floor contact
The door is closed to see whether the seal meets the floor along its full width. If the floor is uneven, a thicker seal or a threshold may be added.
Adjust the opener close limit
A new, thicker seal changes where the door meets the floor, so the opener's travel limit may need a small adjustment so the door does not reverse.
Do it yourself, or call?
Replacing a bottom seal is one of the few garage door jobs many handy homeowners can do, as long as the springs are working and the door can be safely held open. The hardest part is finding the right profile for your retainer. Perimeter stop molding is a straightforward carpentry job.
Call a technician if the retainer is damaged, the bottom section is rusted or rotted, the door is uneven so one side gaps, or the door is hard to hold open. Those usually point to a bigger problem, such as worn springs or a bent section.
Never remove the bottom bracket or loosen anything on the corners of the door while replacing a seal. The lift cables attach there and are under spring tension.
Keeping out pests and drafts
Mice can get through a gap the width of a pencil, and a garage with a torn seal is an easy way into a house. A tight bottom seal, intact perimeter stops and a sealed gap between the door sections, using a door with section-joint seals, keep most pests out. For attached garages, a good seal also keeps cold air from creeping under the door into the house and helps an insulated door do its job.
Water that gets in anyway
A seal can only do so much. If water reaches the garage by running down a driveway that slopes toward the door, it will find its way over or around the seal in a heavy storm. A rubber threshold creates a small dam, and a trench drain across the driveway in front of the door is a more permanent fix, though that is a job for a paving or drainage contractor rather than a door technician.
If the garage floor is lower than the driveway, or water comes up through cracks in the slab, the seal is not the problem. On low-lying streets near the South Shore, and along rivers and creeks upstate, garages also take on water during flooding, which no seal will stop.
Where calls are connected
Calls about weather seals are taken across Long Island and upstate New York. On Long Island: Nassau County and Suffolk County. Upstate: Albany, Rensselaer, Saratoga, Schenectady, Warren, Washington, Columbia, Greene, Schoharie, Montgomery, Fulton, Otsego, Delaware counties.
Questions
Weather seals: questions
How often should a garage door bottom seal be replaced?
It depends on sun, salt and use, but many last five to ten years. Replace it when it is cracked, flattened or no longer touches the floor along its whole length.
My floor is uneven. Will a new seal fix the gap?
A thicker bottom seal can fill small dips. For bigger gaps, a floor threshold, or both together, usually works better.
Why does water come in even with a new seal?
If the driveway slopes toward the garage, water can flow over the seal. A threshold and better drainage at the driveway edge help. Also check the side seals, which can let wind-driven rain in.
Do I need a new retainer, or just a new seal?
If the retainer channel is straight and not rusted through, a new seal is enough. A bent, corroded or missing retainer should be replaced at the same time.
Why does my door reverse after a new bottom seal?
A thicker seal meets the floor sooner, so the opener may sense resistance and reverse. Adjusting the close limit or force, as the opener manual describes, usually fixes it.
Related
Often needed at the same time
Need help with weather seals?
Call (914) 353-8667. Answered day and night.