Garage door symptoms
Rain keeps getting under my garage door
Water coming under a closed garage door almost always gets past a split or shrunken bottom seal, often helped by a driveway that slopes toward the garage. A new seal stops many leaks; sloped driveways and sunken slabs usually need a threshold too.
Updated
Get things off the wet floor, then find where the water enters
Lift boxes, cords and tools off the concrete, and keep extension cords out of standing water. During the next steady Portland rain, note whether water slides under the middle of the door, sneaks in at a corner, or seeps up through a crack in the slab. Each route has its own fix, and a photo of the wet spot lets us name it.
Likely causes, most common first
A split or shrunken bottom seal is the usual way in, followed by driveways that drain toward the door.
- Most common
The bottom seal has split, shrunk or slipped out of its channel
The sign: Water comes in as a band along the door, and the rubber is cracked, short at one end, or sagging loose.
The fix: Slide in fresh rubber of the matching profile, with a new retainer if corrosion has opened up its edges. Garage Door Weather Seal and Threshold Replacement, from $149
- Common
The driveway drains toward the garage
The sign: In heavy rain a sheet of water runs down the driveway and piles against the door, getting in even where the seal looks sound.
The fix: Set a rubber threshold in adhesive across the opening as a low dam, with a new seal that closes onto it. Garage Door Weather Seal and Threshold Replacement, from $149
- Common
The slab has sunk at the door line
The sign: A puddle collects in the same low spot just inside the door after every storm, or the garage floor sits below the driveway apron.
The fix: Raise the sealing line with a threshold matched to the depth of the low spot. Garage Door Weather Seal and Threshold Replacement, from $149
- Less common
The door stops or bounces back before it seals
The sign: The rubber is in good shape but never quite touches down, or the door reverses off the floor, often since an opener swap.
The fix: Reset the down limit and force so the door lands firmly every time, and check the photo eyes if it keeps backing up. Garage Door Opener Repair, from $149
- Less common
The bottom of the door itself has rotted or rusted
The sign: A wood bottom rail has gone dark, soft or crumbly, or rust has chewed through the bottom of a steel door so the retainer wanders.
The fix: Replace the bottom section, or the whole door if that panel design has been discontinued, then seal the new edge. Garage Door Panel and Section Replacement, from $449
- Less common
Wind drives rain past the side seals
The sign: Wet streaks start at the jambs and run down the back of the door during storms with wind behind them.
The fix: Install new stop molding with a soft flap that presses evenly on the door from floor to header. Garage Door Weather Seal and Threshold Replacement, from $149
What you can safely check in two minutes
A garden hose and a dry afternoon will show you the water's route before you spend anything.
- With the door closed, have someone run a garden hose on the driveway while you watch the bottom edge from inside with a flashlight.
- Look along the bottom rubber for splits, short corners, or lengths that have slid out of the channel.
- Find where the nearest downspout empties. One that dumps onto the driveway uphill of the door sends roof water straight at it.
- Clear leaves and grit from any trench drain across the driveway, then check that it still carries water away.
- Press a fingertip into the lowest rail of a wood door. Soft, dark wood there means rot has started.
Why Portland rain finds the bottom of the door
Portland rain is steady more than dramatic, and weeks of it test the bottom of a garage door harder than any single downpour.
NOAA's 1991 to 2020 normals for the Portland airport show about 37 inches a year falling on roughly 157 days, with November, December and January the wettest months. Vancouver's Pearson Field runs slightly wetter. A seal that seemed fine through a dry September gets its real test in late fall.
Wood takes the worst of it. The Forest Products Laboratory's Wood Handbook puts outdoor wood in Portland near 17 percent moisture in December before it is ever splashed, close to the 20 percent mark above which decay can take hold. The lowest rail of a wood door sits right in the splash zone.
Seal, threshold or drainage: which one stops your leak
Split rubber needs a new seal, a driveway that drains toward the door or a sunken slab needs a threshold, and roof or ground water needs drainage work.
We fix everything at the opening itself and tell you plainly when the rest is a gutter, drainage or concrete job for another trade.
| Where the water comes from | What stops it | Worth knowing |
|---|---|---|
| Splits or shrinkage in the bottom rubber | New bottom seal | Usually a single-visit fix |
| A driveway that drains toward the door | Threshold plus a new seal | Works on runoff, not deep ponding |
| A low spot in the slab at the opening | Threshold sized to the dip | A badly sunken slab may need concrete work |
| Wind-driven rain at the jambs | New stop molding and side seals | Check the jamb wood near the floor |
| Roof water landing at the door | Extend or reroute the downspout | A gutter fix, not a door part |
| Water rising through slab cracks | Slab or groundwater repair | No door seal reaches it |
When the driveway runs downhill to the garage
A threshold turns the edge of the slab into a low dam, and on a driveway that drains toward the garage it is usually the piece that finally keeps the floor dry.
Steep ground in the Southwest Hills and other parts of the metro leaves some driveways no choice but to slope toward the door. In steady rain the water arrives as a thin sheet, which a threshold turns aside well.
It is not a flood wall. Water ponding several inches deep against the door calls for a trench drain or regraded concrete, since a threshold that tall would make the opener reverse.
Water under the door: common questions
Why does rain only get under my garage door during heavy storms?
Heavy storms bring more water and wind than a slightly worn seal can handle. A downpour sends a sheet of water down a sloped driveway, and gusts push rain sideways at the jambs. A leak that appears only in big storms usually points at driveway slope or side seals.
Will a threshold stop water coming under the garage door on a sloped driveway?
Usually, as long as the water runs past the door rather than pooling deep against it. The threshold forms a low ridge that the rubber closes onto, turning sheet water aside. When rain collects faster than it drains, a trench drain or regrading is the lasting fix.
Is water coming under the garage door damaging the door itself?
It can, slowly and from the bottom up. A wood door wicks splash into its bottom rail until rot sets in, and a steel door rusts along the lower edge until the seal no longer stays put. Catching it while only the rubber is bad keeps the repair to a seal instead of a section.
Why is water coming up through my garage floor instead of under the door?
That points to the slab or the ground beneath it rather than the door. Water seeping from cracks or joints in the middle of the floor arrives from below or from the side, where no door seal reaches. A drainage or concrete contractor is the right call for that, while we take care of the opening itself.
Can I replace the bottom seal myself to stop rain getting under the garage door?
On many steel doors, yes: the old rubber slides out of its retainer channel and new rubber slides in. The tricky parts are matching the profile and working safely under a raised door. Call instead if the retainer is corroded, the door is wood, or the door drifts when raised partway.
How can I tell if gutters are causing the water under my garage door?
Watch the downspouts nearest the garage during a steady rain. If one empties onto the driveway uphill of the door, or a gutter spills over above the opening, roof water is landing right where the seal has to hold it back. Extending or rerouting that downspout often does more for a wet floor than any seal upgrade.
Related pages
Areas we cover for this
Calls about a water under the door come in from Bridlemile, Felida, Hillsdale and every other part of the metro we serve.
Ready to get the door moving again?
Call with the symptom, or text a photo of the door and the opener, and we will name the part and the posted price before anyone drives out.