How long can a roof leak go unnoticed?
Often weeks, because insulation soaks up water and the ceiling below only stains once it is saturated. During a wet Portland winter, a slow leak can run for a month or more. By then, framing and insulation are wet, and mold can have started. Check the attic after big storms.
A quick look into the attic with a flashlight after a hard rain is the best habit. You are looking for dark patches, wet insulation, water trails on the underside of the roof deck, and any daylight where there should be none.
If you find a wet area, photograph it, note the date and call a roofer. If the ceiling below is wet too, call us.
Is it a roof leak or condensation?
A leak follows rain and shows up near a roof penetration, valley or damaged shingle. Condensation forms on cold surfaces during cold, humid weather and appears across a wide area, often with frost on nails. A moisture pattern and an attic inspection usually settle which it is.
Poor ventilation, bath fans that vent into the attic and missing insulation can make condensation a winter problem. It can soak insulation and stain ceilings, but fixing it means ventilation, not shingles.
A technician and a roofer may both look. We read the moisture, and the roofer reads the roof.
Does moss on a roof cause leaks?
Moss holds water against shingles and lifts their edges, so it can contribute to leaks and wear over time. It does not always cause one. A roofer can judge whether moss is cosmetic or a sign of deterioration, and gutters should be kept clear in any case.
In the Pacific Northwest, moss is a fact of life on shaded north slopes. Cleaning methods differ and some damage shingles, so ask the roofer how they handle it.
Clearing valleys and gutters before the wet season starts is cheap protection against leaks.
What does a technician check in the attic and ceiling?
The technician looks for dark or flattened insulation, water trails on the underside of the roof deck, stained rafters and daylight where there should be none. Below, meters and a thermal camera show how far the water spread across the ceiling and into walls. Readings guide how much is removed.
Attic work is slow and tight. The technician moves along walkways or boards, avoids stepping between joists, and takes photographs of each wet area.
If the attic is finished, the check includes knee walls and the area behind the drywall, using meters through the surface before any cutting.
Should the leak be fixed before drying starts?
Yes, or at least at the same time. Drying equipment cannot finish a job while rain still enters, so a roofer should stop the leak first or protect the opening. Extraction of standing water and removal of soaked insulation can begin immediately, because delay only makes it worse.
In practice the order is flexible. Water and ruined materials come out first, the roofer protects the opening, and drying runs once the roof is closed.
Tell both trades about the other. A roofer who knows a crew is drying the attic can leave access for it.
What does a wet-season roof checklist look like?
Before the October rains, clear gutters and valleys, look for lifted or missing shingles, check flashing around chimneys and vents, and trim limbs that hang over the roof. After a major storm, look into the attic. These small habits catch most leaks before they reach a ceiling.
A summer inspection costs less in time and trouble than a January leak. The dry months, when July and August bring only about half an inch of rain, are the working window.
If you cannot get on the roof, a roofer can inspect it, and binoculars from the ground will show missing shingles.
- Clear gutters and downspouts
- Check flashing and vent boots
- Trim overhanging limbs
- Look into the attic after storms
