Signs of Damaged Roof Shingles
Most roof damage is visible before it becomes a leak — if you know what to look for. This guide explains the signs of damaged shingles on a Bellevue roof, what each sign means, and when it is a repair and when it is a warning that the roof

Most roof damage is visible before it becomes a leak — if you know what to look for. This guide explains the signs of damaged shingles on a Bellevue roof, what each sign means, and when it is a repair and when it is a warning that the roof is nearing the end of its life.
Missing, Lifted and Flapping Shingles — Wind Damage and Failed Seal Strips
A missing shingle is the clearest sign, but a lifted tab is just as important. Wind lifts the edge, breaks the seal strip, and leaves the shingle able to flap. From the ground, look for tabs that do not lie flat, or a patch that looks darker than the rest of the roof.
Cracked, Curled and Cupped Shingles — Ageing Asphalt Shingles in Bellevue
Cracks come from thermal movement, impact and ageing. Curling — edges turning up — and cupping — edges turning down — usually mean moisture imbalance or thermal ageing. Curled shingles cannot seal, and they are easy targets for the next windstorm.
Need shingle repair in Bellevue? Call now for a free inspection and a written quote.
Granule Loss and Bare Patches on Asphalt Shingles — What It Means
Granules protect shingles from sun and weather. Finding granules in gutters is normal in small amounts; bare patches and large amounts in the gutters mean the shingles are wearing out. A roof with widespread granule loss is losing its protection.
Moss, Algae and Dark Streaks on Roof Shingles — Gloeocapsa Magma in Bellevue
Green moss holds moisture against shingles and lifts their edges. Black streaks are usually Gloeocapsa magma, an algae that feeds on the limestone filler in asphalt shingles. Both are common on shaded Bellevue slopes, and both shorten shingle life if left untreated.
What to Do Next — Shingle Repair and Roof Inspection in Bellevue
If you see one or two damaged shingles, book a repair — it is usually a localised fix. If you see several signs at once, or they cover most slopes, book an inspection and ask honestly whether repair or replacement is better value. Do not climb on the roof to check — use binoculars from the ground, or call us.
Need professional help? If this describes your roof, our shingle roof repair in Bellevue, WA service covers it. Call (425) 738-3670 or request an estimate.
Frequently Asked Questions — Roof Shingle Repair in Bellevue, WA
How do I know if my shingles need repair?
Look for missing, cracked, curled or lifted shingles, granules in the gutters, dark streaks, or a stain on a ceiling. A few damaged shingles is usually a repair. Widespread curling, heavy granule loss, repeated leaks in different spots, and a roof over 15–20 years old in Bellevue’s wet climate usually point toward replacement.
What does granule loss mean?
Granules protect asphalt shingles from sun and weather. Some loss is normal with age, but heavy loss — bare patches, or large amounts of granules in gutters — means the shingles are wearing out and losing protection. An inspection shows whether it is normal ageing or a repair-or-replace decision.
Why are my asphalt shingles curling?
Curling is usually thermal ageing, moisture imbalance, or poor ventilation — edges turn up (curling) or down (cupping). Curled shingles cannot seal properly and are easy targets for wind. Replacing the shingles without fixing ventilation or moisture usually repeats the problem.