Those black streaks on your roof aren't dirt — they're Gloeocapsa magma, an algae that thrives in South Florida's humidity. It's everywhere: on shingle roofs, tile roofs, even concrete. And it's not just ugly.
Algae-covered roofs retain more heat, forcing your AC to work harder and raising energy bills. The algae feeds on the limestone filler in shingles, accelerating granule loss and shingle degradation. On tile roofs, algae and lichen hold moisture against the surface, promoting deterioration of the underlayment below.
Perhaps most importantly: many shingle manufacturers can void your warranty if you allow biological growth to go untreated. A $300 cleaning protects a $15,000+ roof investment.