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How to Remove Algae From CertainTeed Roof Shingles

CertainTeed is an American manufacturer of building materials, including asphalt shingles for commercial and residential roofs. Like all roofing materials, asphalt shingles are prone to algae growth. Algae plants do not develop roots and thus do not cause the same amount of damage to your roof as moss and other growths. Nevertheless, algae, usually green or black, can make your roof look old and discolored and thus you should remove it.

Algae is sometimes confused with moss, which is more harmful to roofs.
  1. Push a bristle scrub brush mounted on a pole down the roof to scrape away the algae. This will be relatively easy, as algae plants do not develop roots. Do not push up the roof, as this may damage the bond between shingle layers.

  2. Remove remaining pieces of algae with a power washer. Avoid using chlorine bleach as a roof cleaner, as chlorine bleach may remove the natural color from the shingles, accelerate metal gutter corrosion, and kill ground vegetation.

  3. Place a copper strip, available at most roofing supply stores, under a row of shingles at the top of the roof. Expose at least four inches of the copper from the edge of the shingles. When it rains, the copper molecules will wash down the roof and create an environment that is poisonous to algae.