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Roof Cleaning · Northern Virginia
Professional Roof Cleaning for Asphalt, Metal & Tile Roofs in Northern Virginia
Lawn Theory soft-washes roofs across Northern Virginia — no pressure, ever. Our low-pressure treatment kills the algae and moss behind those black streaks at the root, protects your shingle warranty, and typically buys your roof years of extra life.
The Short Answer
Most Northern Virginia roof cleanings run $450–$1,200, driven by roof size, pitch, and how established the algae or moss is. We soft-wash only — low pressure plus shingle-safe chemistry — which is the method asphalt shingle manufacturers recommend, so granules stay put and warranties stay intact. Results typically last 3–5 years because the treatment kills growth at the root instead of rinsing the surface. Every job starts with a free walkthrough and ends with a written, line-item quote in 24–48 hours — no pressure, no surprises.
What's Included
Every Roof, Cleaned the Manufacturer-Approved Way
Our roof cleaning service covers every material and every problem Northern Virginia rooftops develop — each roof gets the chemistry and technique it actually needs, never a one-size-fits-all blast.
- Soft-wash treatment — low-pressure application that kills algae, moss, and lichen at the root — never high pressure on shingles.
- Black streak removal — the Gloeocapsa magma algae behind dark streaks is eliminated, not just rinsed to return in weeks.
- Moss & lichen treatment — established growth is treated and released naturally without tearing granules off with it.
- Gutter-line rinse — runoff is rinsed from gutters and fascia so treatment never streaks your siding below.
- Landscaping protection — plants, mulch beds, and lawn areas are pre-wetted and covered before any treatment.
- Shingle-safe chemistry — manufacturer-approved cleaning solutions that protect your roof warranty.
- Before & after photos — you see the roofline results without climbing a ladder.
- Aftercare guidance — written re-treatment timeline and prevention advice for your specific tree cover and shade.
Roof Types We Soft Wash
Asphalt shingles — the majority of Northern Virginia roofs — get a true soft wash: low pressure and manufacturer-approved chemistry, because high pressure strips the granules that protect shingles from UV. Metal roofs get a gentler detergent mix that removes oxidation film without spotting panels. Tile and slate are treated with controlled application to protect brittle edges, and cedar shakes get a moss-first treatment that preserves the wood's natural oils.
What drives your price and timeline: roof size and pitch (steeper roofs need more safety setup), buildup severity (established moss takes more treatment than first streaks), material (each gets its own chemistry), and access (multi-story homes and tight lots change equipment needs). Most roofs are done in a half day — and you don't need to be home.
How We Work
Our Roof Cleaning Process
Consultation
We walk your property, identify each surface material, oil stains or algae buildup, and any landscaping or access concerns before quoting.
Proposal
A written, line-item quote within 24–48 hours — surface-specific method, price tier, and scheduling options.
Wash & Rinse
Correct PSI and detergent for each surface, applied with proper technique, then a thorough rinse — protecting plants, pets, and adjacent surfaces.
Local Knowledge
What Northern Virginia Roofs Actually Deal With
- Gloeocapsa magma thrives in NoVA humidityThe airborne algae behind black roof streaks feeds on the limestone filler in asphalt shingles — and Northern Virginia's humid summers give it a nine-month growing season. Once established, it spreads roof to roof through the neighborhood on the wind.
- Mature tree cover keeps north slopes dampThe region's oak and pine canopy shades large sections of roof for most of the day. Shaded, north-facing slopes stay damp after every rain and dew cycle — which is exactly where moss and lichen establish first.
- Moss physically lifts shingles as it growsMoss doesn't just sit on the surface — its root structures work under shingle edges and lift them, letting wind-driven rain reach the underlayment. Treating it early is dramatically cheaper than repairing what it causes.
- Algae growth ages shingles years earlyGrowth holds moisture against the shingle surface through every freeze-thaw cycle and slowly consumes the limestone filler. Roofs that stay clean routinely outlast streaked ones by years — on a $15,000+ asset.
- HOA streak letters are common hereCommunities across Fairfax, Loudoun, and Prince William counties flag visible roof staining in their appearance standards. We provide a treatment date and before/after photos if your HOA asks for proof of compliance.
- Spring and fall are the treatment windowsSpring treatment resets the roof before the summer growing season; fall treatment clears the year's growth before winter locks moisture in. We clean roofs whenever temperatures reliably stay above freezing.
Why Lawn Theory
Why Homeowners Choose Us For Roof Cleaning
No Pressure. Ever.
We never put a pressure washer on a roof. Soft washing — low pressure plus the right chemistry — is the only method shingle manufacturers approve, and the only one we use.
No Pressure. Ever.
We never put a pressure washer on a roof. Soft washing — low pressure plus the right chemistry — is the only method shingle manufacturers approve, and the only one we use.
No Pressure. Ever.
We never put a pressure washer on a roof. Soft washing — low pressure plus the right chemistry — is the only method shingle manufacturers approve, and the only one we use.
No Pressure. Ever.
We never put a pressure washer on a roof. Soft washing — low pressure plus the right chemistry — is the only method shingle manufacturers approve, and the only one we use.
Roof Cleaning Across Northern Virginia
Soft-wash roof cleaning across Arlington, Alexandria, Fairfax, Loudoun & Prince William counties. Pick a county to see where we work.
Get My Free EstimatePopular Areas in Fairfax County
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What Neighbors Say
Trusted on Homes Like Yours
“We hired Lawn Theory for pressure washing and landscaping. It is like we have a brand new home. Five stars!”
“They explained why they'd soft-wash our deck instead of blasting it with a wand, and I appreciated that. Came out clean without a single splintered board.”
“Written quote same day, on time for the appointment, and our HOA letter about the driveway staining is officially resolved. Would use again for our patio next.”
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Questions
Roof Cleaning — Common Questions
How much does roof cleaning cost in Northern Virginia?
Most homes land between $450 and $1,200. Roof size, pitch, and how established the algae or moss is drive the price — a first-time treatment on a heavily streaked two-story colonial costs more than maintenance on a rambler. Bundling roof cleaning with house washing or gutter brightening on the same visit lowers the combined cost, and every quote is written and line-item.
Is soft washing safe for asphalt shingle roofs?
Yes — it's the method the Asphalt Roofing Manufacturers Association recommends. Low pressure plus the correct cleaning solution removes growth without stripping the protective granules or voiding your shingle warranty. High-pressure washing on shingles causes permanent damage, which is why we never put a pressure washer on any roof.
What causes the black streaks on my roof?
Gloeocapsa magma — an airborne algae that feeds on the limestone filler in asphalt shingles. Northern Virginia's humidity and tree cover make it thrive, and it spreads house to house on the wind. Rinsing hides it for a few weeks; soft washing kills it at the root so the streaks stay gone for years.
How long does a roof cleaning last?
Typically 3–5 years in Northern Virginia. Heavily shaded roofs or homes under mature tree cover may see growth return sooner — we assess your specific shade and tree exposure at the walkthrough and give you a realistic re-treatment window in writing, not a one-size-fits-all promise.
Will roof cleaning damage my plants or landscaping?
No — protecting the yard is literally the other half of our business. We pre-wet and cover landscaping, control runoff at the gutter line, and rinse everything after treatment. Beds, lawns, and ornamentals come through the process untouched.
Does a clean roof actually extend roof life?
Yes, measurably. Algae and moss hold moisture against shingles through every freeze-thaw cycle and consume the limestone filler that gives shingles their flexibility. Removing growth typically delays replacement by years — a few hundred dollars of maintenance protecting a $15,000+ asset.
Do I need to be home during the cleaning?
No. We need access to an outdoor spigot and advance notice of pets or gate codes — that's it. You get before-and-after photos of the roofline and a written summary either way, so you see exactly what changed without climbing a ladder.
Free Interactive Quiz
Does My Roof Need Cleaning?
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Written, line-item quotes in 24–48 hours. No pressure, no generic ballparks.