What Causes Black Streaks On Roof Shingles

While not immediately damaging they can prematurely age shingles.

What causes black streaks on roof shingles.

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. Algae may be mistaken for soot dirt or tree droppings most of which typically produce only localized discoloration. They re actually algae otherwise known as gloeoapsa magma and they are as nasty as they are resilient.

Black streaks on shingled roofs are a common though mysterious sight. As the blue green algae. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma. Most black streaks form on the northern slopes of roofs where it s darker and wetter ideal for algae growth.

Over time this algae accumulates developing a black outer coating which causes stains on roof shingles. Why are there dark streaks on my roof. Black streaking on roofs is a common problem. This algae growth usually begins as small spots and then eventually becomes visible streaks.

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. Algae growth on asphalt shingles. Here s what they are and what to do about them.

Algae growth may cause discoloration on roofs resulting in brown or black streaks on a rooftop.