Finding and fixing roof leaks in Vancouver, WA

Roof leaks are rarely where they look. Water enters at one spot, runs along the top of a rafter or the underside of the decking, and drips through the ceiling several feet away. That is why so many leak repairs fail: someone patches the area directly above the stain while the real entry point keeps letting water in. Our leak repair work starts with tracing, not guessing.

We look for water trails, darkened wood and nail tips with rust in the attic, then match them to what we see on the roof. Common culprits include pipe boots, step flashing, chimney flashing, valleys and exposed nails. Once we find the entry, we fix it and confirm that the path is dry. If the source is not obvious, we may run a controlled water test.

Why the stain is rarely under the leak

Water follows gravity and surface tension. Once it gets past a shingle or flashing, it moves downhill along the underlayment, wicks along the decking or runs down the side of a rafter until it finds a low point. On a typical Vancouver ranch with a shallow attic, the drip can show up six or eight feet from where the water entered. On a vaulted ceiling, it may travel even farther before it shows.

Wind changes the picture too. A leak that shows up only during a strong east wind usually means rain is being pushed sideways under shingle tabs, past a ridge vent or behind wall flashing, not that there is a hole in the roof. A leak that appears only in long, steady rain points more toward a worn valley, a split pipe boot or a flashing seam that slowly lets water through.

How we trace a leak to its source

We start in the attic when there is safe access, because that is where the water leaves its trail. We look for stained wood, wet insulation, rusty nail tips and dark streaks on rafters. We measure from fixed points, like a vent pipe or a wall, so we can find the same spot from the roof. Up top, we check every opening and seam uphill of that point before we decide what to fix.

• Attic inspection for stains and wet insulation
• Measured layout from attic to roof surface
• Check of every penetration uphill of the stain
• Controlled water test for hard-to-find leaks
• Moisture check after the repair

The parts that leak most often

Pipe boots are near the top of the list. The rubber collar around plumbing vents dries out and cracks after years of sun, and water runs straight down the pipe into the attic. Step flashing along walls, dormers and chimneys is next, especially where siding or stucco work disturbed it. Valleys, where two roof planes meet, carry more water than any other part of the roof and wear faster, particularly when fir needles pack in.

Other common sources include exposed nail heads that were never sealed, skylight curbs, bath and kitchen exhaust vents, and satellite dish mounts screwed straight through the shingles. Ice dams cause leaks in the occasional cold snap, but they are less common here than condensation. If your attic is poorly vented, moisture from the house can condense on the decking and drip, which looks like a leak but needs a ventilation fix instead.

When the leak is really a ventilation problem

Not every wet attic has a roof leak. In winter, warm, moist air from bathrooms, kitchens and laundry rises into the attic. If the attic does not vent well, that moisture condenses on the cold underside of the decking and drips onto insulation, often in many spots at once. We check for beads of water on nail tips, blocked soffit vents and bath fans venting into the attic. If that is the cause, we tell you and point you to a ventilation fix instead of selling a roof repair.