Drive through Great Bridge, Greenbrier, Kempsville or Wards Corner and you'll see it on roof after roof: dark black streaks running down the shingles, usually worst on the north side. Homeowners often worry it's a leak or a failing roof. Most of the time, it isn't.
What causes black streaks on roofs?
Those streaks are an airborne algae that thrives in warm, humid places like coastal Virginia. It feeds on the limestone filler in many asphalt shingles, which is why it spreads across a roof over time. Shade from tall pines and hardwoods, common on wooded lots in Chesapeake and Virginia Beach, makes it grow even faster.
Is roof algae a problem or just cosmetic?
At first it's mostly cosmetic. But algae, moss and lichen hold moisture against your shingles, and moss can lift shingle edges over time. A streaked roof also makes an otherwise beautiful home look older, which matters if you're thinking about selling.
Never pressure wash a shingle roof
Blasting a roof with a high-pressure washer knocks the protective granules off your shingles, can void a manufacturer's warranty and can force water under the shingle edges. It's one of the most expensive DIY mistakes we see.
How we clean roofs: low-pressure soft washing
We soft wash roofs with low pressure to prevent damage to your shingles. A detergent solution is applied gently, left to break down the algae, moss and lichen, then rinsed at low pressure. Because the growth is treated at the root, roofs stay clean much longer than a quick rinse would. We protect your plants and rinse the walls and gutters below too. Learn more about roof soft washing.
How long does a clean roof stay clean?
Most roofs stay clean for a few years after a soft wash. Roofs under heavy tree cover may need it sooner. Keeping your gutters clean helps too, since clogged gutters keep the roof edge wet.
Roof cleaning near you
We clean roofs throughout Chesapeake, Virginia Beach and Norfolk. Every roof gets a free, upfront quote based on its size, pitch and how much growth there is.
Frequently asked questions
Are black streaks on my roof mold?
They're almost always algae, not mold from a leak. It thrives in humid coastal air and feeds on the limestone in asphalt shingles.
Is it safe to pressure wash a shingle roof?
No. High pressure strips the protective granules and can void your warranty. A low-pressure soft wash is the safe way to clean shingles.
How much does roof cleaning cost in Chesapeake?
Roof pricing depends on size, pitch and growth, so we give every roof a free, upfront quote. Military and veterans save 10%.
Rick Monceaux is the owner of All In One Power Washing in Virginia Beach. He has been cleaning homes and businesses across Virginia Beach, Chesapeake, Norfolk and the rest of Hampton Roads since 2010. Licensed & insured. More about Rick.
