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.

The most common culprit is actually a blue green algae known as gloeocapsa magma that is spread by airborne spores. Household bleach can damage asphalt due to its high sodium content. There is some concern regarding the use of chlorine based products on asphalt roofs. Unlike algae moss can be detrimental to asphalt shingle performance.

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. Though often attributed to an accumulation of dirt defective shingles mold or mildew. 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.

What causes black mildew on shingles on north side of roof and how can get rid. Some black stains on asphalt roof shingles are caused by a black algae typically gloeocapsa magma. These black roof algal stains are sometimes misnamed or misidentified as a black fungus or even a mildew. 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.

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