Roof Leak Detection & Repair

Step 1 — Interior trace. We start where the water shows. Note the exact ceiling position, look at staining shape (round = direct overhead drop, elongated = water traveled along a member), check for paint blistering, drywall sag, and trim staining. On a sloped attic we look up the rafters from the stain to find the entry point. On a flat ceiling we measure carefully and translate to exterior coordinates.

Step 2 — Attic inspection. This is the step most roofers skip. We go into the attic with a flashlight and FLIR thermal camera. We look at the underside of the deck for staining (dark patches = water trail), check for daylight at penetrations, examine framing for moisture, and verify ventilation is adequate. About 30% of 'roof leaks' turn out to be condensation from inadequate attic ventilation — fixable with ridge vent + soffit work, not a roof repair.

Step 3 — Exterior climb. We physically walk the roof — not a binocular inspection from the lawn, not a drone fly-over without close-up access. We check every detail in the catchment zone above the interior stain: shingle field for missing/lifted/cracked tabs, ridge cap, valley flashing, sidewall step flashing, chimney flashing (head, sides, sill, counter), pipe boots, skylight curbs, exhaust vents, and dormer-roof intersections.

Step 4 — Thermal imaging (FLIR) where the leak source isn't obvious. After rain or during a controlled hose test, a FLIR camera shows the moisture trail under shingles or in underlayment that's invisible to the eye. We use FLIR E8 and FLIR One Pro cameras — calibrated, not consumer-grade phone attachments.

Step 5 — ASTM E1105 water testing on hard-to-find leaks. The ASTM standard for water-penetration testing of installed roof systems — we run a controlled hose flow at calibrated rates starting low on the roof and working up, isolating zones until water reproduces inside. The right tool for chronic 'only sometimes' leaks that defy visual inspection.

Step 6 — Written report. Every diagnosis ends with a one-page report: photos of the failure, photos of the diagnostic trail, the recommended repair scope, line-item pricing, and our honest call on whether the failure is part of a bigger pattern that warrants more than just patching this one spot.

Condensation, not a leak. Cold roof deck plus warm humid attic air equals condensation on the underside of the deck. Water drips onto the insulation, shows as a ceiling stain. Looks identical to a real leak from below. The tell: condensation issues show up in winter without precipitation. The fix: ridge + soffit ventilation rebalancing, not a roof repair.

Gutter overflow. Clogged or under-sized gutters can overflow during heavy rain, water runs back under the shingle eave and into the soffit. Shows as staining at the exterior wall. The fix: gutter cleaning or upsize, not a shingle repair.

Ice dam history. Last winter's ice dam pushed water under the shingles into the eave underlayment. Stained the ceiling. The actual breach is up where the ice was — and it may not re-leak until next winter. Fix: ice & water shield extension, attic ventilation, possibly heated cables.

Plumbing leak masquerading as a roof leak. Bathroom directly under attic, ceiling stain at the bathroom exterior wall. Looks like a roof leak from the bath vent. Often turns out to be a slow-drip plumbing leak inside the wall. We rule this out before scoping roof work.

HVAC condensate. Furnace humidifier or AC condensate line backed up into the attic, drained onto the ceiling. Not a roof leak at all. Common in homes with attic-mounted air handlers.

Pipe boot rubber failure (8-12 year service life). The black rubber gasket around plumbing vent pipes cracks from UV. Water enters at the pipe, runs down inside the boot, drips onto the deck. The single most common real roof leak we fix.

Step flashing failure at sidewall. Step flashing pieces aren't woven properly with each shingle course on the original install, or the original step has corroded through. Water gets behind the siding and runs down the framing.

Chimney flashing. Counter flashing has pulled out of the mortar joint, step flashing is failing along the sides, or there's no cricket behind a chimney wider than 30 inches. Water runs down the upper face of the chimney, gets behind the step, into the attic.

Valley failures. Open metal valleys can fail at fasteners or where the closed-cut shingle valley above lost its adhesive seal. Often shows as a ceiling stain in a room directly under the valley.

Ridge cap loss. A wind-lifted ridge cap shingle exposes the felt or ice & water shield beneath. Looks fine from the ground. Causes leaks during driving rain.

Skylight curb / flashing. The step flashing around an old skylight curb has failed, or the curb itself rotted. Ceiling stain near the skylight, but the breach is at the uphill or side edge.