Why Do Roofs Get Black Streaks?

Why do roofs get black streaks? The black streaks running down roofs are actually a hardy algae called Gloeocapsa magma. As the blue-green algae accumulate, they develop a dark, hardened outer coating, which results in the black stains you see. The algae feed on the limestone in shingles. Read more on www.familyhandyman.com Roofs are a … Read more