WHY DO PORTLAND ROOFS GROW SO MUCH MOSS?
Q:Why is moss such a big problem in Portland?
Todd:“Because our climate is basically perfect for it — constant moisture, shade, cool temperatures, and lots of tree coverage. Moss loves Portland roofs.”
Q:Is moss just cosmetic or actually damaging?
Todd:“It’s definitely damaging. Moss traps moisture against the shingles and slowly lifts them over time. That’s when leaks start happening.”
Q:Why do some roofs get moss faster than others?
Todd:“Usually heavy shade, poor drainage, and north-facing roof slopes. Homes under large fir trees are especially vulnerable.”
Q:Can homeowners remove moss themselves?
Todd:“Light cleaning from the ground is okay, but walking on a mossy roof is dangerous. We’ve seen people cause more damage trying to pressure wash or scrape shingles.”
Q:Does pressure washing ruin roofs?
Todd:“On asphalt shingles — yes, it often does. High pressure removes the protective granules and shortens the roof’s lifespan.”
Q:What’s the safest way to deal with moss?
Todd:“Gentle professional treatment and regular maintenance. The earlier you catch it, the easier and cheaper it is to manage.”
Q:How often should Portland roofs be checked for moss?
Todd:“At least once a year. Twice is even better if your home sits under trees or gets heavy shade.”
Q:What happens if homeowners ignore moss for years?
Todd:“Eventually shingles curl, water gets underneath, decking softens, and repairs get expensive fast.”
