Roof soft wash: what to charge (or expect to pay)
The typical US rate for roof soft wash is $0.50 – $1.00 per square foot, adjusted for soil level. Below: how the price is built, what pushes it up or down, and how to quote it line by line.
Typical price range
| Soil level | Multiplier | Effective rate |
|---|---|---|
| Light (maintenance clean) | ×1.00 | $0.50 – $1.00/sq ft |
| Medium (typical job) | ×1.15 | $0.58 – $1.15/sq ft |
| Heavy (algae, neglect) | ×1.35 | $0.68 – $1.35/sq ft |
Sources (verified September 18, 2026): Angi — roof pressure washing, $0.50–$1.00 per sq ft; method: ARMA algae bulletin and GAF TAB-R-102 (no high pressure on asphalt shingles).
What moves a roof price
Roof cleaning is soft washing by definition — and this is not just trade habit: the Asphalt Roofing Manufacturers Association (ARMA) and shingle makers like GAF state explicitly that high-pressure washing must never be used on asphalt shingles, because it dislodges granules, shortens roof life and can void warranties. The approved method is a diluted sodium hypochlorite solution applied and rinsed at low pressure. The cost driver is chemistry, not time — a proper SH mix, surfactant, plant protection and runoff control (wash water must stay out of storm drains under the Clean Water Act and local NPDES rules). Black streaks (gloeocapsa magma) respond well; moss takes longer. Steep pitch and three-story access push quotes to the top of the range. At the published range, a 2,000 sq ft roof prices at 2,000 × $0.50–1.00 = $1,000–$2,000.
Quoting it in writing
WashQuote prices roof soft wash by square footage with the soil factor built in, applies your minimum job charge automatically, and exports a professional PDF quote while you are still on the customer's driveway. Free, no account, nothing leaves your phone.
Frequently asked questions
How much does roof soft washing cost?
$0.50–$1.00 per sq ft of roof area. At that range a 2,000 sq ft roof prices at $1,000–$2,000 depending on pitch, access and moss or algae severity.
Why not pressure wash a roof?
ARMA and shingle manufacturers warn that high pressure strips granules from asphalt shingles, can cause premature roof failure and voids warranties. Soft washing kills the growth chemically at low pressure — it is the manufacturer-approved method.