Garage Door Bottom Seal Checks for Puget Sound Homes

If you find a wet line on the garage floor after a storm, start with the garage door bottom seal. It is the rubber or vinyl strip along the bottom edge of the door. Around Puget Sound, doors stay wet through much of fall, winter and spring, so this strip does a lot of work. Most checks take a few minutes and a flashlight. A few problems sit close to parts that should be left to a technician, and we'll point those out.

Why does a garage door bottom seal wear out faster on some homes?

Exposure is a big part of it. Winter storms in the Puget Sound lowlands usually bring wind-driven rain from the south and southwest, so south-facing garage doors take the most weather. If your door faces that way, check it first and check it more often. Rain pushed sideways can find a gap that a light drizzle would miss.

Shade matters too. Lots under tall evergreens stay damp longer, and that encourages moss, mildew and rot on doors and trim. On those homes the seal and the lower panel may rarely dry out between storms. A soft, slimy or green seal is often a sign it has been wet for a long time.

How do you check a garage door bottom seal for wear?

Close the door on a dry day and go inside the garage with a flashlight. A helper outside can watch for light coming through.

• Turn off the garage lights and look along the floor for daylight under the door.
• Press the seal with your thumb. A healthy seal usually springs back, while an old one can stay flat.
• Run your hand across the full width and feel for cracks, splits, torn ends or hard spots.
• Check that the seal sits snug in its retainer, the metal or vinyl channel that holds it, and is not sagging out.
• Look at both bottom corners, where the seal meets the side weatherstripping. Small gaps there can let in water and pests.
• After the next rain, look for a muddy line or puddle just inside the door.

One weak spot doesn't always mean the whole seal is done. If it fails most of these checks, replacement is probably the better choice.

Why is water still coming in when the seal looks fine?

Debris is a common cause. Evergreen needles, leaves and moss tend to collect along door bottoms, thresholds and tracks in this region. A thin ridge of needles can hold the seal just off the concrete, and water follows that path. Sweep the threshold, wipe the bottom of the door, then close it and look for daylight again. If the gap is gone, regular sweeping through fall may be all it needs.

The slab can be part of the problem as well. Concrete that dips or slopes can leave low spots a standard seal won't reach. In that case a different seal style may work better than an exact copy of the old one.

If you live near the water, take a close look at the retainer. Salt air near Puget Sound speeds corrosion on exposed steel hardware. A rusted or bent retainer can grip a new seal poorly and make swapping it much harder.

Can you replace the seal yourself?

On many steel doors, a handy homeowner can slide the old seal out of its channel and slide a matching one in. Profiles vary, so bring the old piece or a clear photo when you shop.

Know where to stop. The lift cables attach at the bottom brackets on each corner, and those cables are held under tension by the springs. Do not loosen, remove or pry on those brackets for any reason, even to free a stuck seal. If the seal won't come out without touching them, leave it. Springs and cables can cause serious injury, and they are not a do-it-yourself job.

Also pay attention to how the door moves. If it feels heavy, closes unevenly or sits lower on one side, don't force it. Those signs can point to a balance or spring problem that a new seal won't fix.

What should you do if the seal freezes to the floor?

Wait for it to thaw instead of pressing the opener button again and again. Lowland snow and ice aren't frequent here, but during a freeze the bottom seal can freeze to the concrete. If the opener keeps pulling against it, the rubber may tear and the opener may be strained.

Skip the shovel or pry bar, since a blade can slice the seal. A milder afternoon often loosens it. Before the next cold night, sweeping standing water and wet needles off the threshold may help keep the seal from sticking.

When is it time to call for garage door repair?

Call when the problem goes beyond the rubber strip. A dented, rusted or rotting bottom panel can keep even a new seal from sitting flat. The same goes for a corroded retainer, a crooked door or one that is hard to lift. Before you reach out, note which way the door faces, where water or light gets in and how smoothly the door runs. Photos of the seal ends and the floor line help too.

If water keeps finding its way under your door, or the door itself seems off, National Door can take a look as part of our garage door repair service. Tell us what you're seeing through our contact form, and add a photo or two if you have them.