Low pressure only
High pressure strips granules off asphalt shingles and can void manufacturer warranties. Soft washing relies on a sodium hypochlorite based mix and dwell time instead of mechanical force, which is slower per square foot.
Free roof soft wash cost calculator
Roof Soft Wash Cost Calculator — price it before you climb the ladder.
Turn roof area, algae/moss level, story height, and chemical cost into an accurate roof soft wash (pressure washing) price. Soft washing uses low pressure and chemical treatment, so pricing runs on treatment time and safety access, not raw square-foot speed.
Calculate roof wash price01
Roof soft wash calculator
Build a job price
Pick a growth level to load typical defaults, then adjust with your own production rate and costs. Share the result with a client or copy it into your notes.
Recommended price
Price for this job$0$0.00 per sq ft
Labor hours0 hrs
Job duration0 hrs
Direct cost$0
Expected profit$0
Price breakdown
Labor$0
Chemicals$0
Equipment & safety gear$0
Overhead$0
Profit$0
Use the result as a planning baseline. Verify roof pitch, material, growth severity, access, and local pricing before quoting a job.
Roof soft wash guide
Why roof washing is priced differently from concrete
Material changes the chemical mix
Tile and metal tolerate different concentrations and rinse requirements than asphalt shingle. Always match the treatment to the manufacturer's cleaning guidance for that material.
Story height drives safety cost
Ladders, roof anchors, harnesses, and extension wands add real setup time and liability exposure on 2-story and steep-pitch roofs that a single-story ranch home does not require.
Landscaping and runoff protection
Pre-wetting and rinsing plants near the drip line, and covering or diverting runoff from gutters, protects landscaping from the chemical mix and should be priced as separate prep time.
Reading roof growth severity
Turning what you see on the roof into an accurate estimate
Black streaks vs. moss
Black streaking is typically gloeocapsa magma algae and rinses off with a standard soft wash mix and dwell time. Moss and lichen have root structures that grip the shingle and often need manual loosening before rinsing, which is why heavy growth carries a longer multiplier.
North-facing and shaded sections
Roof sections that stay shaded or damp regrow algae and moss faster and often need a stronger mix or a second treatment pass, even when the rest of the roof is only lightly affected.
Repeat customers regrow slower
A roof treated in the last 12-18 months usually needs a lighter, faster maintenance treatment rather than a full heavy-growth job — track treatment history so repeat customers are not overpriced.
Never estimate roof pitch from the ground alone
Steep or complex rooflines increase both safety setup time and the story-height multiplier. Confirm pitch and access before finalizing a bid, not after the crew is on site.