Dark streaks creep across the shingles. Moss thickens along the shaded slope. Most homeowners shrug, because the roof still keeps the rain out. That delay costs money. Algae and moss trap moisture against shingles, lift their edges, and strip away the granules that shield the roof from the sun. A cosmetic issue turns into curled shingles, clogged gutters, and repair bills that arrive years too early. Professional roof cleaning breaks that cycle. This guide covers what grows o
