What Are Those Black Stains on The Roof?

Those black stains are a hardy type of blue-green algae called Gloeocapsa Magma.  The algae appear as

dark stains on shingles that can run the length of the roof.


How Does a Roof Get Algae?

Algae spread from one infected roof to another via airborne spores.  These spores land randomly on a roof

and root.  A protective sheath creates the dark color the algae forms to protect itself from UV rays.


How Does It Grow?

Algae require moisture and proper temperatures to grow. The algae are feeding off the limestone filler that

is used in the manufacture of the shingles.  Algae are found predominantly in the Southeast, but can be

found all up the eastern coast up into the New England states.  The algae generally grow on the northern

exposures of the roof since this exposure generally receives less sunlight.  Algae are well adapted to

extreme conditions.


What Solutions Do I Have?

Your roof can be cleaned by Safe Wash using the Asphalt Roofing Manufacturers Association

recommended methods keeping your roof looking new for years to come.


What NOT to DO!

DO NOT POWER WASH the shingles to clean the shingles.  It is not recommended as it may dislodge

granules, which can lead to premature shingle failure and may void the warranty on the shingles.


Are roof algae only a cosmetic issue?

No, the algae are feeding on the limestone filler in the shingle degrading them. This

shortens the life of the roof.