Black Algae On Roof Shingles

Weather is a factor in algae growth on shingles.

Black algae on roof shingles.

The most common class of roof algae is gloeocapsa magma a bacterium that eats water and expels oxygen. The black streaks are also known as black algae or roof mold. To clean an asphalt shingle roof to remove black algae stains. As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see.

Mix up oxygen based cleaner with water in a five gallon bucket following the instructions. The streaks look like mold but they re actually algae colonies that form in your shingles and feed on moisture and the limestone filler agents in the shingles. Here we discuss the causes of algae growth on roof shingles the effects of these conditions and how to cure or prevent algae formation on roofs. Algae stains on roofs.

To save money most shingle manufacturers have switched to shingles containing asphalt but mostly made up of fillers such as fiberglass and crushed limestone which encourages the growth of algae. I covered our asphalt shingle roof about five years ago with white 50 year guaranteed shingles that had algae prevention treatment but now the entire north side of our roof is black with algae i bought the shingles from lowe s in marianna florida. These algae use the crushed limestone filler as a main food source. I am really disappointed the treated shingles didn t work.

Algae grow most often on wood and asphalt shingles or concrete tiles especially if they do not get a lot of sunlight. If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs. The algae feed on the limestone in shingles. Technically the black streaks on roofs are a form of algae known as gloeocapsa magma.

The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss. Here s why algae grows on roofs. Roof algae generally have a black green hue.