How Do You Get Rid of Blue-Green Algae on Roofs?

Dark stains or streaks on asphalt roofing systems are common. They are often blamed on dirt, mold or mildew, but they are actually from gloeocapsa magma or blue-green algae. While this algae usually isn’t harmful, it creates an eyesore.

Here are ways to remove blue-green algae from your roof and prevent it from coming back.

Blue-Green Algae on Roofs

The black stains you see on your roof aren’t the algae itself, but a hard, dark coating it creates to protect itself from the sun’s harmful ultraviolet rays. Algae is airborne, meaning if your neighbor has it, it’s likely that you’ll get it too. It usually grows in the north and west areas of the home. According to the Asphalt Roofing Manufacturers Association (ARMA), there’s no scientific evidence that algae cause damage to asphalt shingles. But that doesn’t mean you should just leave it there

Treatment and Prevention

At Earl W. Johnston Roofing, LLC, we offer professional roof cleaning services that can take care of your algae problem. You can count on us to effectively remove these microorganisms and prevent them from growing back. We also specialize in installing tile, low-slope and metal roofing systems.

The ARMA recommends using a 1:1 solution of chlorine bleach and water on affected roofs. Apply the solution to the roof and rinse after 15 to 20 minutes. Don’t use any cleaning solution not recommended by the manufacturer.

You can prevent algae growth on your roof problem by investing in GAF StainGuard® Shingles. This product features a Time-Release Technology with specially engineered capsules that are infused with thousands of copper microsites. They release ten times as much algae-killing copper than standard copper-coated mineral granules.

For reliable roofing services, choose Earl W. Johnston Roofing, LLC. We install metal, asphalt and tile roofing systems. Call us at (954) 989-7794 or complete our online form to request a quote. We serve clients in Hollywood, Weston and Ft Lauderdale, FL.