I am talking about your asphalt shingle roof on your home or commercial building. The two types of algae I am referring to are the “black algae” and just regular old greenish moss. These normally occur in the more humid climates of the U.S.
Air born algae can cause damage and or make your roof look ugly. Black algae looks like black streaks running downward on the shingle roof but does not damage the shingle. Moss, however, can grow into the shingle and cause damage if not taken care of. Both types can be cleaned off by a roofer or by a homeowner even. Just be careful up there!
The way to avoid the stuff from growing is to be sure when you get a new roof that your roofing contractor is installing an algae resistant shingle. CertainTeed manufacturer calls their algae warranty “Streak Fighter” and it comes in 10 and 15 year durations. Even on a lifetime shingle the max is 15 years because the copper coating on the granules wears off with weather over time before the shingle wears out. This copper coating is what resists the algae growth. CertainTeed and other roofing shingle manufacturers do not offer an algae resistant warranty on their 20 year products.
Contact me to talk about this if you like. Thanks!
Robert Andrews, II
Andrews Roofing Company, Inc.
757 Mount Vernon Ave
Portsmouth, VA 23707