Roof Flashing Repair in Seattle
Here's the industry's open secret: most roof leaks aren't shingle problems. They're flashing problems. Flashing is the metal that waterproofs every place the roof meets something else — a wall, a chimney, a valley, a skylight, a vent. When those joints fail, water gets in, and it happens years before the shingles themselves wear out.
Seattle's wind-driven rain finds flashing failures that would never leak in a calmer climate. A gap that stays dry in a straight-down drizzle becomes a leak when a southerly pushes rain sideways into a wall transition for six hours.
The bad fix is everywhere in this city: a thick smear of roofing tar over the failed metal. It buys a season or two, then cracks and traps water behind it. The right fix is replacing the flashing itself — cutting in new step flashing, re-lacing valley metal, resealing counterflashing into masonry — so the joint sheds water the way it was designed to.
Signs this is your problem
- Leak or stain where a roof slope meets an upstairs wall
- Water appearing around the chimney after wind-driven rain
- Rust streaks or visibly lifted metal along valleys
- Tar smears from previous 'repairs' that are cracking
- Interior leak that comes and goes with wind direction
How the repair works
- Trace the jointFlashing leaks show up far from their source. We test and trace to the failed joint, not just the wet spot.
- Open the detailShingles or siding at the failure are carefully lifted to expose the flashing line.
- New metal, woven rightNew step, valley, or apron flashing integrated with underlayment and shingles in the correct overlapping order.
- Seal and verifyCounterflashing sealed, the detail water-tested where practical, and photographed.
What it costs
Flashing repairs in Seattle typically run $600 to $2,200 depending on the location and how much surrounding material has to come up. Chimney and wall transitions sit at the higher end; single vent flashings at the lower.
The Seattle factor
Seattle's older housing stock is full of complex rooflines — dormers on Ballard bungalows, additions on Beacon Hill boxes, and rooftop decks on newer townhomes — and every transition is a flashing detail that has to be right. Wind exposure off the Sound makes West Seattle and Magnolia wall flashings work harder than almost anywhere else in the city.