Black streaks on asphalt shingles are typically caused by Gloeocapsa magma, an algae that feeds on limestone filler in shingles.
Left untreated, this algae — along with moss and lichen — can trap moisture against your roof, shortening its lifespan.
Professional roof cleaning uses a low-pressure, soft-wash method with an algaecidal solution, never high-pressure washing, which can dislodge granules and void shingle warranties.
Regular roof cleaning every 2–3 years can significantly extend the life of your roofing investment.
