Why Algae grows on Roofs in North Florida

Why do so many roofs in the South East get dirty so fast? the answer is because the climate, temperatures and rain make for ideal conditions for algae to grow and thrive on roofs, and Jacksonville and surrounding areas are no exception. With regular type asphalt shingle roofs, it can take as little as two years before the algae on the roof can begin to become visually noticeable. Before long, it will spread to all parts of the roof.
Usually it will start on the North side of the roof, and begin as just a subtle streaking. After a short while the streaking will turn into an overall coverage of almost the entire roof. Sometimes, if you didn't know any better, you would assume that roof is actually a dark color because it is so infested it may show no signs of the original color. Many times though the algae on a roof will avoid certain areas which can leave a clue to what the roof should look like if it were clean, and free of algae.
These areas are usually in spots that rain doesn't touch and roof areas right underneath vents that are made of galvanized steel. The reason for this is because the galvanization has zinc in it and the algae the grows on roofs doesn't like to grow where the zinc washes off underneath the vent. For more information about Why roofs get algae, and what can be done to prevent it, contact an experienced Roof Cleaning Service in your area.