This algae growth usually begins as small spots and then eventually becomes visible streaks.
What causes black streaks on roof shingles.
Why are there dark streaks on my roof.
The streaks are caused by a type of algae known as gloeocapsa magma.
If you re seeing black streaks running along your roof chances are you ve mistaken them for dirt or even mold.
Black streaking on roofs is a common problem.
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.
The black streaks running down roofs are actually a hardy algae called gloeocapsa magma.
Algae growth may cause discoloration on roofs resulting in brown or black streaks on a rooftop.
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.
Over time this algae accumulates developing a black outer coating which causes stains on roof shingles.
Areas of the country with low humidity have fewer instances of roof streaks while the problem is relatively common in the southeast where it s more humid and warm.
While the streaks do not cause a great deal of damage they can cause the shingle to age prematurely.
As the blue green algae.
Black streaks on shingled roofs are a common though mysterious sight.
They re actually algae otherwise known as gloeoapsa magma and they are as nasty as they are resilient.
Algae arrive on the rooftop through the air in the form of spores or clumps of cells.
Here s what they are and what to do about them.