What Causes Mildew On Roof Shingles

If you live in a humid area of the country you ve probably seen unsightly dark streaks on asphalt shingle roofs.

What causes mildew on roof shingles.

These black roof algal stains are sometimes misnamed or misidentified as a black fungus or even a mildew. Damaged flashing gaps or holes in the flashing can also serve as entryways for water into your attic. Black algae stains may be mistaken for but are not extractive bleeding a product cosmetic defect. There is some concern regarding the use of chlorine based products on asphalt roofs.

I suffer from two of. Moss can cause the leading edges of the shingles to lift or curl which darkening the shingles to restore the inherent beauty of the wood will involve cleaning staining and sealing each shingle for routine mildew and light mold this step can be eliminated. Answered by a verified home improvement expert we use cookies to give you the best possible experience on our website. The most common culprit is actually a blue green algae known as gloeocapsa magma that is spread by airborne spores.

Missing shingles a heavy storm can blow shingles off a roof especially on houses where the shingles have been weakened due to the growth of moss mold mildew or algae. Though often attributed to an accumulation of dirt defective shingles mold or mildew. What causes black mildew on shingles on north side of roof and how can get rid. Apparently the sodium causes an electrochemical reaction that reduces the elasticity of the asphalt leading to stiffness brittleness and curling of the shingles.

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.