Problems With Your Asphalt Shingles?
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. 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 — a theme we explore in why no roof lasts forever.
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. If you’re comparing materials, it’s also worth reading about tile roof problems.
Asphalt shingles last just 15–20 years, and curling, granule loss, and streaking all shorten even that.
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. If it’s the latter, it’s the right moment to consider whether your next roof should be asphalt again or something that lasts decades longer.
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, you get a 50+ year roof backed by a lifetime warranty. Compare the long-term cost in metal roof vs. shingles, or request a free quote.
Frequently Asked Questions
Why are my asphalt shingles curling?
Curling happens as asphalt ages and its oils bake out under UV, making shingles brittle and warped. It’s a sign the roof is nearing the end of its 15–20 year life.
What causes black streaks on a roof?
The black streaks are a blue-green algae feeding on the limestone filler in asphalt shingles. They’re common in humid climates and, along with moss, hold moisture that shortens roof life.
Is granule loss serious?
Yes. Granules protect the asphalt from UV and add fire resistance. Once they wash into the gutters, the exposed shingle degrades rapidly — a reliable sign the roof is wearing out.
Can I clean my asphalt roof myself?
Be careful — pressure-washing strips protective granules and can void some shingle warranties. Use only gentle, manufacturer-approved methods, or hire a professional.
When should I replace asphalt shingles?
Widespread curling, bald spots from granule loss, persistent moss, or any interior water signs mean it’s time for a professional assessment and likely a replacement.
Does a metal roof have these problems?
No. A metal roof has no granules to lose and won’t rot, curl, or streak the way asphalt does, and it lasts 50+ years versus asphalt’s 15–20.
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Last updated June 8, 2026 · Reviewed for accuracy by the Interlock SEO Desk.