There is some concern regarding the use of chlorine based products on asphalt roofs.
What causes mildew on roof shingles.
Household bleach can damage asphalt due to its high sodium content.
Though often attributed to an accumulation of dirt defective shingles mold or mildew.
Black algae stains on asphalt singles some black stains on asphalt roof shingles are caused by a black algae sometimes misnamed as a black fungus or even a mildew such as that shown in the photograph here.
The most common culprit is actually a blue green algae known as gloeocapsa magmathat is spread by airborne spores.
It s actually just a blue green algae spread by airborne spores.
As i mentioned before moss typically grows in the cracks between each shingle.
If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs.
Like mold mildew is a cancerous growth on damp surfaces.
Black streaks green or white spots round lichens mosses green moss that spreads across your roof.
As it grows thicker it lifts and loosens shingles and allows water to leak through.
These black roof algal stains are sometimes misnamed or misidentified as a black fungus or even a mildew.
The black mold like stains and streaks that appear on roofs particularly light colored asphalt shingles is actually a blue green algae gloeocapsa magma.
I suffer from two of.
If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs.
It is easily spread and causes those colorful stains on so many roofs.
Some black stains on asphalt roof shingles are caused by a black algae typically gloeocapsa magma.
Also moss absorbs water when it rains and retains it for long periods which can lead to mold bacteria and the decay of the roof s framing over time.
Although mold can grow in your roofing materials if water gets trapped somewhere if you see any of the following on top of your roof algae are more likely your problem.
Apparently the sodium causes an electrochemical reaction that reduces the elasticity of the asphalt leading to stiffness brittleness and curling of the shingles.
Though often attributed to an accumulation of dirt defective shingles mold or mildew.
Commonly found in climates with warm humid summers it does no damage to the roofing but it certainly does looks bad.
The most common culprit is actually a blue green algae known as gloeocapsa magma that is spread by airborne spores.
Black algae stains may be mistaken for but are not extractive bleeding a product cosmetic defect.
Moss is attracted to moisture and therein lies the problem.
As moss spreads it carries increased amounts of moisture and this can set into the wood of shakes and shingles and cause a roof to rot.
