The streaks are caused by a type of algae known as gloeocapsa magma.
How did my roof get the black streaks.
As the blue green algae accumulate they develop a dark hardened outer coating which results in the black stains you see.
The wind carries the spores of this algae onto your roof.
Gravity pulls this coating down leaving black streaks on the impacted roof.
The algae feed off of the limestone within the roof shingles.
It s easy to miss once it begins but the black patch is an indicator that a predatory bacteria gloeocapsa magma has taken up residence on your.
Roof algae is most prevalent on north and west facing shingles and in neighborhoods with lots of mature trees.
The algae will worsen and become more noticeable each year trapping moisture and causing premature shingle aging and granule loss.
The most common type is known as gloeocapsa magma also known as blue green algae.
Most likely it started as a small circular patch a slight discoloration from the normal color of your shingles.
The great news for homeowners is that the most common causesof these black streaks are algae called gloeocapsa magma.
The black roof stains are caused by a form of algae that has been around for years typically found in the woods on the north side of trees or on exposed rocks.
The black streaks are also known as black algae or roof mold.
If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs.
Although it may look like mold or fungi these unsightly black streaks or smear like stains may indicate a type of roof algae known in technical terms as gloeocaspa magma.
The algae feed on the limestone in shingles.
Over time this algae accumulates developing a black outer coating which causes stains on roof shingles.
Thankfully it isn t harmful to your health like mold.
With each passing year the algae will grow and become more and more noticeable.
This blackish algae creeps it way across neighborhood roofs gradually turning your home s asphalt shingles an ugly dark brown or black.
The algae then thrive on the moist crevices of your asphalt tiles.
Technically the black streaks on roofs are a form of algae known as gloeocapsa magma.
This algae growth usually begins as small spots and then eventually becomes visible streaks.
The wrong way to remove black streaks from your roof there is a temptation among homeowners to try to address gloeocapsa magna with power washing.
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.
The black streaks running down roofs are actually a hardy algae called gloeocapsa magma.
Here s why algae grows on roofs.
