How Portland's Climate Affects Your Roof
Portland's mild but consistently wet climate is brutal on roofing surfaces. Year-round moisture, low evaporation, and shaded conditions create ideal growing conditions for moss, lichen, and algae — all of which trap water against shingles and accelerate decay. Most Oregon homeowners deal with significant biological growth within 8–10 years of a new roof install. Algae-resistant shingles, copper or zinc strips, and proper sun exposure dramatically extend roof life.