What are those black streaks on my roof?

Those black streaks running down your roof do not mean you need a new roof or that it is getting ready to fail, rather you have Algae on your roof.

Algae produce a dark pigment acting like sunscreen protecting the cells from the sun. As this algae accumulates on your roof shingles, the roof becomes less reflective, causing your house to become hotter and cooling bills to go up.

This organism comes in either spores or clumps of cells on your roof top. The north side of your roof gets less sun and more moisture, which makes it a great place for algae to multiply and grow faster on your roof. Asphalt shingles contain limestone, which makes them heavy, durable and reflective. Roof algae over time will consume the limestone and weaken the shingles.

Roof algae is the first wave of attack on your roof,  Algae eventually teams up with fungus to form Lichen. Moss follows next building layers of soil that catches seeds, and bird droppings. By the time grass is growing on your roof, it’s time to get a new roof. Pressure washing can save you money by extending the life of your roof and retaining the beauty and cleanliness of your home.



Roof Cleaning 101 part A

Roofing manufactures ( ARMA ) top 4 roof dangers:

Algae; effects all roofs ( metal, wood, shake, asphalt shingles and tile) lowers property values and deteriorate roofs. Algae thrives in shaded humid areas.

Lichen; effects all types of roofs leads to increased shingle degradation leading to costly repairs or replacement. Lichen loves humid conditions on your home.

Moss;  may lead to roof rot and compromise and compromises the integrity of these areas leading to costly repairs or replacement.

Mold; Effects wood and dry walls. Some molds such as Stachybotrys ( commonly known as black mold ) Can cause health risks and respiratory illnesses. Mold forms fast and can compromise the entire house not just the roof. Mold appears as fuzzy black, green, or brown colored spots and only needs moisture to form in all regions.

Mildew;  Mildew loves warm, humid, rainy climates. Effects roofs with poor drainage or where trees hang over. you can recongnize mildew by its green,black, red, or pink powdery appearance

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