Organic growth (algae, moss, lichen) traps moisture, eats at shingle fillers, and can shorten roof life as well as curb appeal. Removing it early costs far less than premature re-roofing.

They’re colonies of Gloeocapsa magma—a blue-green algae that feeds on the limestone in asphalt shingles and spreads downward in long “drip” lines.

No. ARMA warns that high-pressure spray can lift shingles and void warranties. We use a true soft-wash system that delivers solution at garden-hose pressure.

A professional roof-wash solution (an industry-standard bleach-and-water blend plus surfactant) recommended by the Asphalt Roofing Manufacturers Association. It dissolves algae on contact, then breaks down into salt, water, and oxygen as it rinses away.

Not when applied properly. We pre-wet and, if needed, tarp landscaping, control runoff, and rinse everything afterward—standard plant-protection best practices.

Plan on every 2–3 years in normal conditions, or annually in very humid or shaded spots.

An average roof stays stain-free about 3-5 years before fresh spores can recolonize.

Only if it’s done with excessive pressure or unapproved chemicals. Manufacturer guidance shows that gentle, ARMA-approved soft washing keeps warranties intact.

Whenever possible we treat from ladders or extension poles; on steeper or complex sections, a harnessed technician may step on the roof temporarily, always following fall-protection rules. Soft-wash pressure is lower than a summer downpour, so it won’t drive water under shingles.