Common Asphalt Shingle Problems & What to Do

Asphalt shingles curl, crack, and blow off; lose the protective granules that shield them from UV; and grow moss, algae, and black streaks. Each problem shortens an already short (15–20 year) lifespan. A rust-proof aluminum roof eliminates all of them — no granules to lose, nothing to rot, and a 50+ year life.

Asphalt shingles rarely fail all at once. They decline in a series of small, recognizable symptoms — and learning to read them tells you exactly where your roof is in its life.

Asphalt is the most common roofing material in North America because it's cheap and quick to install, though it's worth comparing that upfront cost against a metal roof's total lifetime value — see our breakdown of whether a metal roof or shingles is cheaper. But it's also a petroleum product with a short life, and as it ages it shows a predictable set of problems. Spotting them early lets you plan a replacement on your terms rather than after a leak.

Below are the asphalt problems to watch for, what each one means, and when to call a professional — plus why a metal roof simply doesn't suffer from any of them. (Other materials have their own known failure points too — see our breakdown of clay or concrete tile roof problems.)

What are the common problems with asphalt shingles?

The most common asphalt shingle problems are curling, cracking, and missing shingles (from age, heat, and wind); granule loss, which exposes the asphalt to UV and speeds its breakdown; and moss, algae, and black streaks that hold moisture and stain the roof. All of them shorten asphalt's 15–20 year lifespan and signal that replacement is approaching. A metal roof avoids every one — it has no granules to lose and won't rot, curl, or streak.

Curling, Cracking, and Missing Shingles

As asphalt ages and its oils bake out under UV, shingles lose flexibility and begin to curl at the edges or cup in the middle. Brittle shingles crack, and wind lifts and tears off the weakest tabs — especially once the adhesive strip has degraded. Each curled, cracked, or missing shingle is an opening for water to reach the decking beneath. Widespread curling and cracking is one of the clearest signs that a roof is near the end of its service life and that patching is no longer enough.

Granule Loss

The colored granules embedded in a shingle's surface aren't just for looks — they shield the asphalt from UV rays and provide a measure of fire protection. As shingles age, those granules loosen and wash away, collecting in gutters and at downspout outlets. Once the granules are gone, the exposed asphalt degrades rapidly under the sun. Finding significant granule accumulation in your gutters is a reliable signal that the shingles are wearing out and the roof's clock is running down.

Moss, Algae, and Black Streaks

In damp, shaded, or humid climates, asphalt roofs grow moss and algae. The dark streaks many homeowners see are actually a blue-green algae feeding on the limestone filler in the shingles. Moss is worse: it holds moisture against the shingles, and in freezing weather that trapped water expands and damages them, while moss roots can lift shingle edges. Beyond the staining, this biological growth actively shortens the roof's life by keeping it wet.

A Word of Caution on Cleaning

It's tempting to pressure-wash a stained asphalt roof, but that's a common mistake — high-pressure water strips away the protective granules and can do more harm than the algae. Worse, some shingle manufacturers' warranties can be voided if the homeowner cleans the roof improperly. Gentle, manufacturer-approved methods exist, but the underlying issue is that asphalt is a porous, organic-friendly surface to begin with — unlike a smooth metal roof that gives moss and algae far less to cling to.

When to Call a Professional

A few isolated issues may be repairable, but widespread curling, bald spots from granule loss, persistent moss, and any interior signs — ceiling stains, attic moisture, or daylight through the deck — mean it's time for a professional assessment. A roofer can tell you whether you're looking at a targeted repair or an approaching replacement.

The Roof That Skips These Problems

Every asphalt problem above traces back to the material itself — a petroleum product covered in loose granules that dries out, curls, and feeds algae. An Interlock aluminum roof has none of those vulnerabilities: there are no granules to lose, no organic material to rot, nothing to curl, and a smooth surface that resists moss. Instead of 15–20 years of gradual decline like the pattern we cover in what you think roofs last forever, you get a 50+ year roof backed by a lifetime warranty.

"I replaced my 9,000-pound asphalt roof with an 800-pound aluminum metal roofing system... reducing seismic load and dramatically cutting summer temperatures inside the house." — David Patton, Corvallis, Oregon · Installed July 2019 · Verified GuildQuality review