Why Do Roofs Get Streaked

This algae growth usually begins as small spots and then eventually becomes visible streaks.

Why do roofs get streaked.

The algae is most commonly gloeocapsa magma a blue green algae that travels and propagates through airborne spores. Dark streaks or roof discoloration caused by algae happens in varying degrees across the u s especially in areas exposed to warm humid conditions. The black streaks running down roofs are actually a hardy algae called gloeocapsa magma. Also algae and fungus can grow together to form lichen the roots of which can wrap around and feed on the granules covering the shingles.

These black streaks are called gloeocapsa magma or gm more commonly called mold or fungus. In the past shingles were constructed using felt and asphalt. 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. This cyanobacteria is a bacteria that get their strength to survive through photosynthesis and the limestone filler found in the composition of shingles.

The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss. Algae dark stains on asphalt roof shingles. As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see. While the dark streaks are unsightly experts tell our team that the greatest danger to the roof is from moisture retention or root damage that algae and other life forms can cause.

The most common type is known as gloeocapsa magma also known as blue green algae.