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