In a wood garage door, rot begins where end grain sits in splash and standing water through a Clark County winter: the bottom rail and the foot of each jamb leg. Caught early, it is a patch: dig out the soft wood, fill, seal and paint. Left alone, it spreads up the stiles and into the screws that hold the hardware.
When the damage runs the width of a section, the repair becomes garage door panel replacement or a rebuilt section, and on a door with several rotted sections it becomes a new door. This guide walks through how to tell which case you have.
Why wood garage doors rot in Clark County
Wood decays when it stays wet, and a Clark County winter keeps the lowest rail of a wood door wet for months at a time.
According to the USDA’s Wood Handbook, keeping wood dry, below 20 percent moisture content, prevents decay from starting or progressing. Its outdoor moisture table has no Vancouver row, but the closest station, Portland, runs between 16.5 and 17.4 percent for November, December and January, before any splash or puddle is added.
That is why rot shows up at the slab line and rarely at the top section. The City of Camas lists the decay hazard for its building designs as moderate, and the oldest housing in our area, near downtown Vancouver and in Kelso and Longview, is the likeliest to still have wood doors and wood jambs.
Where rot starts on a wood garage door
Rot starts in five places, from the bottom rail up to the header trim, so check them in this order with an awl or a small screwdriver and a bright flashlight.
| Spot | What rot looks like there | Usual cause |
|---|---|---|
| Bottom rail of the lowest section | Peeling paint, dark end grain, the tip sinks in | Bare end grain on the bottom edge, a seal that holds water |
| Lower panel corners and joints | Open joints, swollen panels, staining | Water running down the panel and pooling at the rail |
| Jamb legs at the slab | Soft, crumbling foot of the jamb, moss in the gap | End grain on or near concrete, failed caulk |
| Header trim above the door | Soft fascia or brick mold, paint bubbles | Overflowing gutter or missing flashing over the trim |
| Hinge and bracket screws | Screws that spin or pull out by hand | Punky wood behind the hardware |
The last row matters most. On a wood sectional door, the hinges, the top fixture and the bottom brackets are screwed into the wood, and the bottom brackets carry the lift cables under full spring tension.
Rot near the bottom brackets is a stop sign
If the wood around a bottom bracket is soft, leave the door closed and do not touch the bracket, because a fastener pulling out of rotten wood under spring load can let the cable and bracket fly.
The fix starts with unloading the springs. We take the tension off, remove the bracket and cable, replace the rotted section or rail, then re-anchor the hardware into new wood and rewind the springs. A new or rebuilt section usually weighs differently from the old one, so the springs are rebalanced, or resized, to suit the door as it now stands.
The same caution applies to the opener’s top fixture. A loose operator bracket screwed into a soft top rail can tear out when the opener pulls the door down.
How to repair a rotted bottom rail on a wood garage door
A soft spot smaller than your palm, well away from the brackets and hinges, can be repaired with an epoxy wood consolidant and filler.
- Close the door, unplug the opener and throw the manual side lock, so nothing can move the door while you work.
- Probe the edges of the damage until the tip meets hard wood on every side.
- Cut out the soft wood with a chisel or carbide scraper, down to sound fibers.
- Let the cavity dry. Wait for a dry spell, or tent the spot and run a fan. Filling wet wood traps the moisture that caused the rot.
- Brush on a penetrating epoxy consolidant and let it soak into the surrounding fibers.
- Fill with an epoxy wood filler, overfilling slightly, then shape and sand it flush once it cures.
- Prime every bare surface, including the end grain on the bottom edge, which is the side most often left unpainted.
- Apply two coats of exterior paint, then fit a new bottom seal so the rail is not sitting on wet rubber.
How to repair a rotted garage door jamb and header trim
Jamb rot is fixed by cutting out the rotten foot of each leg and splicing in rot-resistant stock, then sealing the cut and keeping the new end grain off the concrete.
On many doors the vertical track brackets are lagged through the jamb into the framing. If the lags sit in soft wood, the track is supported before anything is cut, and the brackets go back into solid material. The perimeter seal and stop molding are reset afterward so they shed water instead of trapping it.
Header rot is a water source problem first. Clean or repair the gutter, add flashing over the head trim, then replace the soft trim. Patching it without stopping the drip just restarts the clock.
Keeping the finish sound so rot does not come back
Paint or stain only protects wood where it is unbroken, so the yearly job is finding the breaks before water does.
Amarr’s care guide says wood doors should be inspected at least once a year and stripped and refinished once visible flaws appear, and it warns that pressure washing can damage the softer surface of wood. Watch the bottom edge, panel grooves and joint lines, and recoat on your door maker’s schedule. A new bottom seal each time the old one flattens keeps the rail off wet rubber.
Can a rotted wood garage door be repaired, or does it need replacing?
Yes, a rotted wood door can be repaired while the rot is local and the door is otherwise straight; a new section makes sense when one section is gone, and a new door when rot or warping runs through several sections.
Wood sections from a current product line can often be ordered to match, while a custom or older door may need a millwork shop to build a section. A one-piece wood door has no sections to swap at all, which our guide to one-piece tilt-up garage doors explains.
If you decide to replace it, a steel or composite door with a wood-look finish trades yearly refinishing for far less upkeep, and new garage door installation includes springs sized to the new door. Text us photos of the bottom rail and jamb, and the posted prices on our prices page show where each option starts.