Professional Roof Washing in Maryland
Low-pressure soft wash that eliminates black streaks, moss, and algae without voiding your roof warranty.
About This Service
Those black streaks running down your roof aren't just cosmetic — they're a living organism called Gloeocapsa Magma algae that feeds on your shingles' limestone filler and accelerates their degradation. Left untreated, roof algae and moss can shorten your roof's lifespan by years, potentially costing thousands in premature replacement. OneNation's professional roof washing service eliminates these threats safely and effectively.
We use only low-pressure soft wash technology for roof cleaning — never high-pressure washing, which can strip granules, crack shingles, and void manufacturer warranties. Our ARMA (Asphalt Roofing Manufacturers Association) compliant process applies a specialized cleaning solution that kills algae, moss, and lichen at the root, then gently rinses it away. Results can last 2–5 years.
What’s Included
- ✓Extends Roof LifespanAlgae and moss physically degrade shingles by retaining moisture and feeding on limestone granules. Our treatment stops this damage and can add years to your roof's life.
- ✓Warranty-Safe ProcessOur soft wash method follows ARMA guidelines and won't void your roofing manufacturer's warranty. High-pressure washing can — and often does.
- ✓Improves Energy EfficiencyDark algae streaks absorb more heat, increasing attic temperatures and air conditioning costs. A clean roof reflects more sunlight and keeps your home cooler.
- ✓Long-Lasting ResultsBecause we kill the algae rather than just washing it away, results typically last 2–5 years — far longer than ineffective DIY methods.
Our Process
Roof Assessment
We inspect shingle condition, identify algae type (algae, moss, or lichen), and determine the appropriate solution strength for your specific roof.
Ground & Gutter Protection
Landscaping and gutters are protected before application. We pre-wet vegetation to neutralize any cleaning solution contact.
Soft Wash Application
Our ARMA-compliant soft wash solution is applied from ridge to eave at low pressure, thoroughly coating all affected areas.
Rinse & Inspection
A gentle low-pressure rinse removes the cleaning solution and dead organic material. We inspect every section and spot-treat any remaining areas.
Plant & Landscape Safe
We pre-wet and protect every plant, shrub, and lawn bordering the work area before we start, and use biodegradable cleaning solutions that rinse clean. If anything in your landscaping is damaged by our work, we make it right at no cost to you.
Our Guarantee
If you’re not satisfied with the roof washing we did, we come back within 7 days and re-clean the area at no charge — no argument, no fine print.
Frequently Asked Questions
Our soft wash process uses low pressure (no higher than a garden hose) and is specifically calibrated to avoid damaging asphalt shingles. High-pressure washing can damage shingles — we never use it on roofs.
Ready for Professional Roof Washing?
Get your free estimate today. We serve Silver Spring, Rockville, Bethesda, Gaithersburg, and all of Montgomery County.