Why Is There A Black Discoloration On Some Asphalt Roofs

The discoloration usually has a brown to black appearance and may be mistaken for fungus growth soot dirt moss or tree droppings.

Why is there a black discoloration on some asphalt roofs. The streaks and discoloration you are now seeing is an accumulation of their dead dark colored cells. Gloeocapsa has the ability to form a protective darkly pigmented outer coating that shields the algae from damaging uv rays. The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss. Why do shingles get algae.

Algae spores are airborne. Today s homeowner serves cookies to analyze traffic and better serve you. The algae was deposited on your roof by wind and or wildlife. These roof invaders require a moisture rich environment usually.

Algae may be mistaken for soot dirt or tree droppings most of which typically produce only localized discoloration. It appears in streaks or patches of slime that can be anywhere from blue green to dark black. One of the common issues i have seen in recent years with asphalt roofing shingles is what is called petroleum discoloration this is where a certain number of shingles might look darker than others on a roof. As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see.

Green or black algae stains. This algae most probably invaded your last roof as well. Gloeocapsa magma is probably the most prevalent of several algae species that contribute to discoloration. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma.

This is what makes those unattractive black streaks on your roof. All species are transported through the air and tend to collect and grow upon roofing structures. The algae feed on the limestone in shingles. Across the entire eastern half of the country roof shingles tend to grow a species of algae called gloeocapsa magma.

Algae growth may cause discoloration on roofs resulting in brown or black streaks on a rooftop. Although algae can be found on all types of roofing it tends to be most common on asphalt shingles. Roof algae rarely poses a threat to the health of the roof. Algae growth on asphalt shingles.