This quality is what distinguishes slate as a suitable roofing material.
Black mold on slate roof.
Like all tile however slate can be prone to mildew and mold particularly if it is installed in a high moisture area like a bathroom a basement or a kitchen.
Commonly found in climates with warm humid summers it does no damage to the roofing but it certainly does looks bad.
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.
Technically the black streaks on roofs are a form of algae known as gloeocapsa magma.
Slate is a sedimentary rock with miniscule layers that easily cleave.
Slate is one of the most durable and popular materials used in construction.
What are those ugly black streaks on my roof.
Believe it or not those black streaks only appear on roofs in certain areas of the country.
Just because you can t see it however doesn t make it any less dangerous.
At best slimy black mold deposits are an eyesore.
For this reason it works as well on a tiled roof as it does on a bathroom floor.
The black streaks are also known as black algae or roof mold.
At worst they can pose serious health risks.
It s easy to let a mold problem sneak up on you on in out of the way places like the roof of your home.
The black mold like stains and streaks that appear on roofs particularly light colored asphalt shingles is actually a blue green algae gloeocapsa magma.
The most common type is known as gloeocapsa magma also known as blue green algae.