Streaks On Roof Shingles

If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs.

Streaks on roof shingles.

If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs. Because the shingles hold moisture for long periods of time algae can begin growing and actually feed off of the limestone in the shingles. As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma.

Algae arrive on the rooftop through the air in the form of spores or clumps of cells. The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss. Though often attributed to an accumulation of dirt defective shingles mold or mildew. Although these dark spots and ugly black streaks on your roof may look like dirt mildew soot or mold what they really are is algae.

They re actually algae otherwise known as gloeoapsa magma and they are as nasty as they are resilient. The most common type is known as gloeocapsa magma also known as blue green algae. When i was flipping through an old issue of weird new jersey i noticed something about a lot of the homes that were featured in the abandoned section almost without fail every photo of an abandoned house would have black streaks on roof shingles. It might be surprising to know that those dark streaks on the shingles are actually caused by algae and not by the usual suspects of tar or dirt.

Technically the black streaks on roofs are a form of algae known as gloeocapsa magma. This algae growth usually begins as small spots and then eventually becomes visible streaks. With each passing year the algae will grow and become more and more noticeable. Black streaks on the north and west facing and shaded areas of your asphalt shingled roof can really wreck the appearance of your home.

Blame the algae those black streaks on your shingles may look like problems with old age or damage but they are really caused by algae specifically gloeocaspa magma is usually to blame for those wavy dark shades that grow as the algae bloom spreads. The black streaks are also known as black algae or roof mold. Over time this algae accumulates developing a black outer coating which causes stains on roof shingles. 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.

The most common culprit is actually a blue green algae known as gloeocapsa magmathat is spread by airborne spores. The algae feed off of the limestone within the roof shingles. The streaks are caused by a type of algae known as gloeocapsa magma.