Black streaking on roofs is a common problem.
What causes black streaks on roof shingles.
As the blue green algae.
While the streaks do not cause a great deal of damage they can cause the shingle to age prematurely.
They re actually algae otherwise known as gloeoapsa magma and they are as nasty as they are resilient.
Here s what they are and what to do about them.
While not immediately damaging they can prematurely age shingles.
This algae growth usually begins as small spots and then eventually becomes visible streaks.
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.
If you re seeing black streaks running along your roof chances are you ve mistaken them for dirt or even mold.
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.
The streaks are caused by a type of algae known as gloeocapsa magma.
Algae growth on asphalt shingles.
Algae growth may cause discoloration on roofs resulting in brown or black streaks on a rooftop.
Over time this algae accumulates developing a black outer coating which causes stains on roof shingles.
The most common type is known as gloeocapsa magma also known as blue green algae.
Most black streaks form on the northern slopes of roofs where it s darker and wetter ideal for algae growth.
Why are there dark streaks on my roof.