Black Mold On Slate Roof

What are those ugly black streaks on my roof.

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. 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. Commonly found in climates with warm humid summers it does no damage to the roofing but it certainly does looks bad. Believe it or not those black streaks only appear on roofs in certain areas of the country.

That s why if. For this reason it works as well on a tiled roof as it does on a bathroom floor. Just because you can t see it however doesn t make it any less dangerous. Technically the black streaks on roofs are a form of algae known as gloeocapsa magma.

At best slimy black mold deposits are an eyesore. This quality is what distinguishes slate as a suitable roofing material. At worst they can pose serious health risks. Those that tend to be the most humid furthermore they will only appear on the north side of the roof.

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 mold like stains and streaks that appear on roofs particularly light colored asphalt shingles is actually a blue green algae gloeocapsa magma. Slate is a sedimentary rock with miniscule layers that easily cleave. Once turned into roofing material slate absorbs water and can naturally de laminate during the freeze and thaw cycles of winter.