If you re seeing black streaks running along your roof chances are you ve mistaken them for dirt or even mold.
What causes black streaks on roof shingles.
Algae arrive on the rooftop through the air in the form of spores or clumps of cells.
The black streaks running down roofs are actually a hardy algae called gloeocapsa magma.
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.
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.
The streaks are caused by a type of algae known as gloeocapsa magma.
While not immediately damaging they can prematurely age 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.
Algae may be mistaken for soot dirt or tree droppings most of which typically produce only localized discoloration.
Black streaks on shingled roofs are a common though mysterious sight.
Here s what they are and what to do about them.
Black streaking on roofs is a common problem.
This algae growth usually begins as small spots and then eventually becomes visible streaks.
Why are there dark streaks on my roof.
Algae growth on asphalt shingles.
Most black streaks form on the northern slopes of roofs where it s darker and wetter ideal for algae growth.