A blue green algae known as gloeocapsa magma could be the reason you have the algae which is spread by airborne spores sometimes it can also be caused by an accumulation of mildew mold dirt or defective shingles.
Blue green algae on roof shingles.
A roof may develop different types of algae lichens and fungi as bacteria take over.
Commonly found in climates with warm humid summers it does no damage to the roofing but it certainly does looks bad.
Algae can grow in moist shaded areas so if a homeowner has trees hanging over their roof tell them to trim them back to let the sunshine warm and dry the roof.
Though often attributed to an accumulation of dirt defective shingles mold or mildew.
The growths on the roof are cyanobacteria or blue green algae a phylum of organisms that has dwelt on earth for about 3 billion years.
According to algae expert michael guiry algae base at references some of these black algae are as identified in the lab blue green or even lichenized algae while others are a diverse group of coccoid algae like our microscope photo of more green algae from a roof sample below that are turning out be be very diverse.
Living in a humid area of the country like florida you ve probably seen your asphalt shingle roofs with unsightly dark streaks on them.
In addition to moisture from rainwater blue green algae also eats the limestone filler that s used to make the asphalt shingle granules.
The most common culprit is actually a blue green algae known as gloeocapsa magma that is spread by airborne spores.
However algae is commonly found on roofs across the usa and canada.
If a new roof is in order then suggest gaf shingles with stainguard protection to help ensure the beauty of a roof against unsightly blue green algae.
If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs.
Many homeowners mistake algae for roof mold in most cases however it is really a blue green type of algae and when it dies it leaves dark streaks on your roof.
As primordial photosynthesizers they were the originators.
Products with stainguard plus algae protection are covered by a 25 year limited warranty against blue green algae discoloration.
Blue green algae usually brings images of lakes and waterways clogged with algae causing damage to the ecosystem not a roof.
Typically it will appear as dark black stains or streaks.
While it doesn t cause substantial damage to the roofing surface the black streaks can certainly make it ugly.
If you ve noticed it on your roof you may have mistaken this common algae for mold or mildew.
See gaf shingle accessory limited warranty for complete coverage and restrictions.