After thousands of roof repair calls across Seattle, we've got a clear picture of where leaks actually start. Same handful of spots, over and over. If you know where to look, you can catch most of these before they turn into drywall damage and mold. Here's our list, ranked by how often they show up on our service tickets.
## 1. Pipe boot flashings
This is the single most common repair we do. Not even close. Our crews replace three to four pipe boots per week across all our jobs.
Pipe boots are the rubber collars that seal around plumbing vents poking through the roof. The rubber dries out and cracks after 8 to 12 years, way before the shingles around them wear out. From inside, you'll see a water stain on the ceiling near a bathroom or kitchen. From outside, the cracked rubber is visible with binoculars. Typical repair runs $250 to $450.
## 2. Chimney flashing
The joint between a chimney and the roof uses two layers of flashing: step flashing along the sides and counter flashing tucked into the mortar joints. As the house settles (and Seattle homes on clay soil settle a lot), that counter flashing pulls away from the brick. Water runs right down behind it.
Inside, the stain shows up on the ceiling or wall near the chimney, often on the uphill side. Outside, look for gaps where metal has separated from mortar. Expect $600 to $1,500 for a full reflash.
## 3. Roof valleys
Valleys are where two roof planes meet, and they funnel a ton of water during our fall and winter storms. Metal valley flashing corrodes over time, and fir needles build up and dam water against the shingles. Once water backs up behind a debris dam, it gets under the shingles fast.
Inside, the stain tracks along the line where the two planes meet. Outside, look for dark discoloration on the metal or piles of debris. Valley repairs typically run $500 to $1,200.
## 4. Skylight curbs
Skylights are great for natural light. They're also leak magnets, especially older Velux units from the '90s. The seal around the curb deteriorates, and the flashing underneath can separate as the frame expands and contracts through seasons of PNW temperature swings.
Inside, you'll notice water staining directly around the frame. It's one of the easier leaks to trace because the source and the stain are in the same spot. Outside, check for cracked sealant or lifted flashing at the corners. Repairs range from $400 to $900, or $1,500 to $3,000 if the whole unit needs replacing.
## 5. Wall-to-roof transitions
This one causes some of the worst hidden damage we see. Where a lower roof meets a wall (think a one-story addition meeting the two-story section), missing kick-out flashing lets water run behind the siding. The roof looks fine, the shingles are fine, but the wall behind the siding is rotting from the inside out.
Inside, you might see staining on interior walls rather than ceilings, sometimes a floor below the actual roof line. Outside, look for bubbling paint or soft spots on the siding near where the roof meets the wall. Repairs run $400 to $800 for the flashing, but if the siding and sheathing are trashed, you're looking at more.
## 6. Ridge caps
Ridge caps take the worst of the wind. During a big Puget Sound storm, gusts lift the cap shingles, and nails work loose over time as the ridge flexes. Once a cap lifts, rain drives straight into the ridge vent and down into the attic.
Inside, you'll see staining along the peak of the ceiling, or water marks on the underside of the ridge board in the attic. Outside, look for lifted or missing cap shingles and nails that have backed out. Repairs run $200 to $500.
## 7. Nail pops
Nails that were driven too deep, not deep enough, or at an angle will gradually work their way back out. Once the nail head breaks through the shingle surface, it creates a tiny hole that water follows straight down. One nail pop isn't a crisis. A dozen of them across a roof section means the installation had problems.
Inside, nail pop leaks cause small, scattered stains that don't seem to follow any pattern. Outside, you'll see small bumps or exposed nail heads on the shingle surface. Individual nail pops cost $150 to $300 to fix, but if they're widespread, get a full roof inspection to assess the bigger picture.
## Why these fail faster in the PNW
Here's the thing about Seattle. We don't get the heaviest rain in the country, but we get constant moisture for eight or nine months straight. A cracked pipe boot in Phoenix might go two years before causing interior damage. That same crack here will have water coming through within weeks. Our climate doesn't give small failures time to stay small.
If you've got a leak that's already active, don't wait on it. We offer emergency roof repair for situations that can't sit. For everything else, catching these problems early during a routine inspection is the cheapest insurance you'll find.
Curious about a specific leak or want help tracking one down? Check out our full guide on how to find and fix a roof leak, or get in touch and we'll get someone out to take a look.
