Quick answer: Plan on garage door bottom seal replacement when the rubber is flat, cracked or torn, or you can see daylight under the closed door. Do it before the October rains. If water still gets in, check the side weatherstripping and the slab. Swapping a seal in a straight retainer is often a homeowner job; bent retainers and bottom brackets go to a technician.
Key takeaways
- Daylight around a closed door, a flat or cracked seal, or a wet stripe inside after a storm means a seal is failing.
- Water under the door usually comes from the bottom seal, the side weatherstripping or the slab. A new seal fixes only one.
- Downtown Portland averages about 6.6 inches of rain in November and 7.4 in December, so close the gaps while the slab is dry.
- Swapping a seal in a straight retainer is often DIY. Bent retainers, crooked doors and bottom brackets are technician work.
How do I know if my garage door seal needs replacing?
Start with the free test. Close the door on a bright afternoon, turn off the garage lights and look along the bottom and both sides. Anywhere light shows through, rain and leaves can get in too.
Other signs the seal is done:
- Bright spots at the bottom corners, where the bottom seal meets the side stops.
- Rubber that stays flat instead of springing back, or has cracked or torn.
- A seal sagging out of its channel.
- A wet stripe inside the door after a storm, or leaves blowing in.
- A side flap that no longer touches the door.
There is no set schedule. The Department of Energy’s guidance on doors notes that weatherstripping wears down with use and recommends checking it every year. That advice is written for entry doors, but it fits garage door seals too. Check yours each late summer.
Bottom seal, side weatherstripping or top seal: which is failing?
Three seals close the gap. The bottom seal is a rubber or vinyl strip on the bottom edge, usually held in a metal channel called a retainer. The side and top seals, often called stop molding, are fastened to the frame, with a soft flap that presses against the closed door.
Where the water lands tells you which one is failing. A wet stripe across the whole width points to the bottom seal or the slab. A wet corner usually means the bottom seal and side stop no longer meet. Drips down the frame point to a side stop.
| Seal | Where it lives | What wear looks like | DIY or call |
|---|---|---|---|
| Bottom seal | Bottom edge of the door | Flat, cracked or torn; daylight at the floor | Often DIY in a straight retainer |
| Bottom retainer | Metal channel holding the bottom seal | Bent, corroded or pulling loose | Call: it can share hardware with the bottom brackets |
| Side weatherstripping | Frame on both sides | Gaps, brittle flap, loose fasteners | Often DIY; call if the wood is soft |
| Top seal | Header above the door | Daylight or drips at the top | Often DIY |
| Threshold seal | Bonded to the slab under the door | Loose ends, cracks, flattened by tires | Often DIY on clean, dry concrete |
If more than one seal is worn, replace them together so the corners close up.
Why is water still getting in after a new seal?
When a fresh seal does not stop the water, look for these causes:
- The wrong seal. A profile that does not match the retainer can sit crooked or stop short of the corners.
- A door that stops short. If the opener stops before the seal meets the floor, the gap stays. Have us reset the opener’s close limit rather than turning up the force setting, then run the reversal test from our guide to the garage door reversal and balance tests.
- A crooked door. A bottom edge that sits lower on one side leaves a gap on the other. It can also signal a cable or spring problem: stop using the door and call.
- The slab or driveway. Water that runs toward the door reaches it no matter what seal you have.
- Condensation. A damp floor on a humid day may be moisture from the air settling on cold concrete. Our article on garage condensation, moss and moisture explains the difference.
Sloped driveways, uneven slabs and threshold seals
A bottom seal can only fill a gap it can reach. Soft rubber bridges a small low spot, not a deep dip or a cracked, settled slab. Many older homes around Portland and Vancouver have slabs that have shifted over the decades, so check the floor before you blame the seal.
A driveway that slopes toward the garage sends runoff straight at the door. A threshold seal helps: a raised rubber strip bonded to the floor where the door closes, working like a small dam. Install it on clean, dry concrete in late summer. If the whole driveway drains toward the house, call a concrete or drainage contractor.
Standing water has one more cost: in a cold snap it can freeze the seal to the slab. NWS Portland puts the average first fall freeze at the airport around November 11. Our guide to a garage door frozen to the ground explains what to do.
How wind-driven Portland rain finds the gap
Only about 3 percent of Portland’s rain falls in July and August, per NWS Portland, and nearly 90 percent falls between mid-October and mid-May. In late summer the slab is dry, so seal problems are easy to miss.
Then the rain arrives in bulk. NWS Portland’s normals for downtown Portland show about 6.6 inches in November and 7.4 in December, the wettest months of the year. NOAA normals give PDX measurable rain on about 18 or 19 days a month from November through January, and Vancouver’s Pearson Field runs a bit wetter than PDX in December and January.
Much of our winter rain rides in on south and southwest winds, which push it sideways into side stops and bottom corners. East winds, NWS Portland explains, funnel through the Columbia River Gorge and blow hardest where it exits. East-facing doors in Troutdale, Gresham and Camas can leak in an east wind and stay dry in a southwest storm.
Garage door bottom seal replacement: what a technician does that a kit cannot
A hardware-store kit is a strip of rubber. On a door with a straight retainer, a level bottom edge and a flat slab, that may be all you need. If you do it yourself, follow the maker’s directions, keep everyone away from the wall button and run the reversal test afterward. If the old seal will not slide out without loosening a bracket, stop there and call us.
What a kit cannot do is tell you why the seal failed. When our technicians at Larry Myers Garage Doors replace a bottom seal, they also:
- Match the seal to the retainer and the door width.
- Replace a bent retainer. On many doors it shares hardware with the bottom brackets, which anchor the cables under spring tension. DASMA, the door manufacturers’ association, says bottom brackets should be adjusted or loosened only by a trained door systems technician.
- Check balance, level, cables, rollers and springs, so a thick new seal is not hiding a crooked door.
- Set the side stops and the opener’s close position, then run the reversal test.
Sometimes the door itself is the problem. A wood bottom section that has soaked up years of rain will not hold a seal, and our garage door installation team can talk through a new section or door.
When to call a professional
Skip the DIY route and call us when:
- The gap is wider on one side, or the door looks crooked.
- The retainer is bent or pulling away from the door.
- The job would put your hands near rusted bottom brackets or cables.
- The wood at the bottom of the door or along the frame is soft.
- Water still gets in after a new seal.
Some findings mean stop using the door today: a frayed or slack cable, a gap in a spring coil, or a door that suddenly feels heavy or hangs crooked. Keep people and pets clear, do not pull the emergency release with the door open, and call.
Our garage door repair technicians handle seals, retainers, cables and rollers across Portland and Vancouver, and same-day service is available. Want to see your options first? Request a free estimate.
Frequently asked questions
What size bottom seal does my garage door need?
It depends on your retainer and door width. Bottom seals come in different shapes, and the edge that slides into the channel must match your retainer. Measure the door’s full width and bring a piece of the old seal when you shop. If nothing matches, a technician can fit the right one.
Can I replace garage door weatherstripping without a pro?
Often, yes. Sliding a new bottom seal into a straight retainer and replacing worn side stops are common homeowner jobs; run the reversal test afterward. Call a technician if the retainer is bent, the door sits crooked, or the work would put you near the bottom brackets and cables, which hold spring tension.
How often should garage door weatherstripping be replaced?
There is no fixed schedule. The Department of Energy recommends checking door weatherstripping every year because it wears down with use. Each late summer, close the door, turn off the lights and look for daylight. Replace any seal that is flat, cracked or torn.
What is the difference between the bottom seal and the side weatherstripping?
The bottom seal is attached to the door and moves with it, sealing against the floor. Side and top weatherstripping, or stop molding, is fastened to the frame and stays put, with a flexible flap that presses against the closed door. The two must meet at the bottom corners, or water gets in there.
When is the best time to replace a garage door seal in Portland?
Late summer, before the rains settle in. NWS Portland notes that nearly 90 percent of the year’s rain falls between mid-October and mid-May, with November and December the wettest months downtown. A dry slab also makes a threshold seal easier to install. The same timing works in Vancouver.
Want the gaps sealed before the rain?
Larry Myers Garage Doors has treated Portland and Vancouver customers like neighbors since 1973: transparent, affordable pricing, same-day service available, no extra charge on Saturdays, work backed by our warranty, and estimates that are always free.
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