10/26/2026
Why does roof moss keep coming back? 🌧️
As October rain gets underway in Tigard and across Portland and surrounding areas, shaded, damp roofs create ideal conditions for moss. Oregon State University Extension notes that cleaning alone may not prevent it from returning if the roof stays shaded and moist.
Two steps can help change the conditions:
• Trim overhanging branches to let more sunlight reach the roof.
• Use a proper soft wash moss treatment. Unlike pressure rinsing the surface, soft washing targets moss at the root without blasting shingles.
Thinking about a roof clean this fall? Call (503) 893-9081 for a free quote.
24-month (2-year) Roof No Green Growth Guarantee, 12-month (1-year) House Wash No Green Growth Guarantee, 30-Day Gutter Cleaning Guarantee, 100% Satisfaction Guarantee.