Algae Growing On Roof Shingles

If you have noticed black spots or streaks on your roof you ve got algae on your roof.

Algae growing on roof shingles.

Algae growth is common on roof surfaces of several materials including asphalt shingles concrete and clay roof tiles and even slate. It can be brown gray blue or green. Algae growth won t cause any structural problems to your roof but it looks ugly and it can damage the shingles over time. The black mold like stains and streaks that appear on roofs particularly light colored asphalt shingles is actually a blue green algae gloeocapsa magma.

Often algae that is identified as green when studied microscopically also looks black or quite dark on a roof surface. A blue green algae known as gloeocapsa magma could be the reason you have the algae which is spread by airborne spores. Although mold can grow in your roofing materials if water gets trapped somewhere if you see any of the following on top of your roof algae are more likely your problem. Black streaks green or white spots round lichens mosses green moss that spreads across your roof.

Commonly found in climates with warm humid summers it does no damage to the roofing but it certainly does looks bad. Algae will grow flush against the shingles and fixtures on your roof. Algae is not a plant but an organism spread by spores.