Short answer
Price a roof soft wash from cost up. Roof area = footprint × pitch factor; hours = area ÷ your door-to-door rate; break-even = loaded labour + SH and surfactant + overhead; price = break-even ÷ (1 − margin). Example: a 2,236 sq ft roof, two-person crew, 4 hours, $40 of chemicals, 35% margin = $523.08.
- Roof area is footprint × pitch factor, where the factor is √(1 + (rise ÷ 12)²). A 6/12 roof is 1.118.
- The same 2,000 sq ft footprint is 2,108 sq ft of roof at 4/12 and 2,828 sq ft at 12/12.
- A two-person crew at $25 wage, 30% burden and 35% margin needs $115.38 per crew hour before chemicals.
- In the worked example the roof prices at $0.234 per sq ft; your rate and chemicals move that number.
- Every figure here is an assumption for one example. Replace each one with your own.
On this page
- How to price soft washing a roof: the formula
- How to measure a roof for soft washing: footprint × pitch factor
- How much to charge to soft wash a roof per square foot (try it)
- How much to soft wash a 3,000 sq ft house roof?
- How to cost SH and surfactant on a roof job
- What is the minimum charge for roof cleaning?
- The common mistakes: floor area, one-person pricing and markup
- Excel formulas for a roof cleaning pricing calculator
- Roof cleaning pricing calculator, app or spreadsheet?
- What to put on your roof soft wash price sheet
- Step-by-step
- FAQ
How to price soft washing a roof: the formula
Price a roof from what it costs you to clean it, then divide by one minus your margin. The per-square-foot number comes out at the end; it is not the starting point.
Search results for this topic are mostly forum posts and national price ranges. Those tell you what someone else charged on their roof, with their crew, their chemical prices and their drive. The five lines below work with your inputs instead, and every figure on this page shows its working.
- Roof area = footprint including overhangs × pitch factor.
- Hours = roof area ÷ your door-to-door production rate (sq ft per hour for the whole visit).
- Labour = hours × people × loaded rate (wage × (1 + burden %)).
- Break-even = labour + SH and surfactant + hours × people × overhead per sellable hour.
- Price = break-even ÷ (1 − target margin).
The method is the same one used for house washes and driveways in the guide to pricing pressure washing jobs. What changes on a roof is the measurement, the crew size and the chemical line, so that is what this page covers.
How to measure a roof for soft washing: footprint × pitch factor
Measure the footprint from the ground (length × width, including the overhangs), then multiply by the pitch factor. You do not need to walk the roof to get a quoting number.
A roof with a rise of R inches per 12 inches of run slopes along the hypotenuse of a right triangle. For every 12 inches across, the surface runs √(12² + R²) inches. Divide by 12 and the pitch factor is √(1 + (R ÷ 12)²). For a 6/12 roof: 6 ÷ 12 = 0.5, 0.5² = 0.25, √1.25 = 1.118. A 2,000 sq ft footprint × 1.118 = 2,236 sq ft of roof surface.
| Pitch | Working | Pitch factor | Roof area (sq ft) |
|---|---|---|---|
| 4/12 | √(1 + 0.111) | 1.054 | 2,108 |
| 6/12 | √(1 + 0.25) | 1.118 | 2,236 |
| 8/12 | √(1 + 0.444) | 1.202 | 2,404 |
| 10/12 | √(1 + 0.694) | 1.302 | 2,603 |
| 12/12 | √(1 + 1) | 1.414 | 2,828 |
This works for any roof where every plane has the same pitch, hips and valleys included, because each plane is its footprint area times the same factor. Where planes differ (a steep main roof and a low porch roof), measure each footprint and apply its own factor. Add dormer faces and skip anything you will not clean. If you quote from a satellite measuring tool instead, check whether its figure is already the sloped area so you do not apply the factor twice.
How much to charge to soft wash a roof per square foot (try it)
Your price per square foot is the job price divided by roof area. For the example roof it is $0.234, and your own production rate and chemical cost will move it more than anything else.
The calculator above starts on the example roof. The rate of 559 sq ft an hour is not a spraying speed. It is the whole visit divided into the roof area: 2,236 sq ft ÷ 4 hours. Those 4 hours are assumptions laid out like this; time your own visits and replace them.
| Task | Hours |
|---|---|
| Drive, ladders, fall-protection setup, pre-wetting plants | 1.0 |
| Mixing and applying the solution | 1.5 |
| Dwell time per the product label, rinsing plants and surfaces | 1.0 |
| Pack-up and drive back | 0.5 |
| Total on the clock | 4.0 |
Worked example: Roof soft wash: 2,000 sq ft footprint at 6/12 pitch = 2,236 sq ft of roof, two-person crew, 4 hours door to door (all inputs are assumptions)
| Item | Value |
|---|---|
| Workers (input) | 2 |
| Hourly wage paid (input) | $25.00 |
| Labour burden % (input) | 30% |
| Materials (input) | $40.00 |
| Overhead for the year (input) | $17,600.00 |
| People in the field (input) | 2 |
| Billable days a year (input) | 220 |
| Target margin % (input) | 35% |
| Jobs a week (input) | 4 |
| Area (sq ft) (input) | 2,236 |
| Production rate (sq ft per hour) (input) | 559 |
| Loaded labour rate (per hour) | $32.50 |
| Crew-hours | 8 |
| Labour cost | $260.00 |
| Overhead per sellable hour | $5.00 |
| Overhead share | $40.00 |
| Break-even cost | $340.00 |
| Price to quote | $523.08 |
| Profit on the job | $183.08 |
| Price if you MARK UP instead | $459.00 |
| Margin you actually keep with markup | 25.93% |
| Lost per job by marking up | $64.08 |
| Lost per year by marking up | $13,328.00 |
| Hours on the job | 4 |
| Price per sq ft | $0.234 |
| Break-even per sq ft | $0.152 |
Computed with the same formulas as the free calculators on this site. Change any input in the calculator above to see your own numbers.
Two people for 4 hours is 8 crew hours. At a loaded $32.50 an hour that is $260.00 of labour. Overhead of $17,600 a year spread over 2 people × 220 days × 8 hours = 3,520 sellable hours is $5.00 an hour, or $40.00 on this job. Add $40 of chemicals and break-even is $340.00; divided by 0.65 that is $523.08.
How much to soft wash a 3,000 sq ft house roof?
A 3,000 sq ft house does not have a 3,000 sq ft roof. Living area counts every floor; the roof covers the footprint once, stretched by the pitch.
A two-story 3,000 sq ft house might sit on a 1,500 sq ft footprint including overhangs. At an 8/12 pitch (factor 1.202) that is 1,803 sq ft of roof, which is smaller than the single-story example above. A steeper roof can slow the crew down, so this example assumes 450 sq ft an hour instead of 559, and $32 of chemicals.
Worked example: Two-story 3,000 sq ft house: 1,500 sq ft footprint at 8/12 = 1,803 sq ft of roof, slower assumed rate for the steeper pitch
| Item | Value |
|---|---|
| Workers (input) | 2 |
| Hourly wage paid (input) | $25.00 |
| Labour burden % (input) | 30% |
| Materials (input) | $32.00 |
| Overhead for the year (input) | $17,600.00 |
| People in the field (input) | 2 |
| Billable days a year (input) | 220 |
| Target margin % (input) | 35% |
| Jobs a week (input) | 4 |
| Area (sq ft) (input) | 1,803 |
| Production rate (sq ft per hour) (input) | 450 |
| Loaded labour rate (per hour) | $32.50 |
| Crew-hours | 8.01 |
| Labour cost | $260.43 |
| Overhead per sellable hour | $5.00 |
| Overhead share | $40.07 |
| Break-even cost | $332.50 |
| Price to quote | $511.54 |
| Profit on the job | $179.04 |
| Price if you MARK UP instead | $448.88 |
| Margin you actually keep with markup | 25.93% |
| Lost per job by marking up | $62.66 |
| Lost per year by marking up | $13,034.00 |
| Hours on the job | 4.01 |
| Price per sq ft | $0.284 |
| Break-even per sq ft | $0.184 |
Computed with the same formulas as the free calculators on this site. Change any input in the calculator above to see your own numbers.
Smaller roof, similar price: $511.54 against $523.08, because the assumed slower rate added hours. Per square foot it is $0.284. This is why a single per-sq-ft figure copied from a forum can be wrong in both directions. The roof area and the hours are separate inputs, and a steep or cut-up roof changes the hours even when the area falls.
The same logic answers the 1,000 sq ft and 2,500 sq ft versions of the question: convert living area to footprint, apply the pitch factor, then price the hours.
How to cost SH and surfactant on a roof job
Cost the chemicals you pour on this roof, not a monthly average. Chemical cost = gallons of sodium hypochlorite (SH) concentrate used × what you pay per gallon + the surfactant used on the job.
The mix strength for a roof is set by the product label and the roofing material, so this page does not give dilution ratios. Follow the label and the safety data sheet for mixing, protective equipment, plant protection and rinsing, and follow local rules on runoff. The pricing point is simpler: once your mix is set, you know how many gallons of concentrate a roof of a given size uses, so the chemical line becomes a number per 1,000 sq ft of roof that you can price every time.
- Track concentrate used per roof for a few jobs.
- Divide by the roof area to get gallons per 1,000 sq ft.
- Multiply by your current price per gallon, and update it when your supplier's price changes.
In the examples, $40 and $32 are assumptions standing in for that calculation. The pressure washing pricing calculator spreadsheet keeps SH and surfactant as their own line on every job, so the cost cannot drift into overhead and disappear.
Pressure Washing Pricing Calculator
The spreadsheet version of this guide for Excel & Google Sheets: type your numbers into the highlighted cells and the formulas do the rest. One-time $39, no subscription, instant download.
See the Pressure Washing Pricing Calculator →Buy now — $39Instant access by email after checkout via Payhip. Want to try the maths first? Use the free calculator — no signup.
What is the minimum charge for roof cleaning?
Your roof minimum is the full price of the smallest roof you would still set up ladders for. With two people for 2.5 hours door to door and $15 of chemicals (assumed), it is $311.54.
Worked example: Roof minimum charge: the smallest roof worth the trip, 2.5 hours door to door for two people (assumed inputs)
| Item | Value |
|---|---|
| Workers (input) | 2 |
| Hourly wage paid (input) | $25.00 |
| Labour burden % (input) | 30% |
| Materials (input) | $15.00 |
| Overhead for the year (input) | $17,600.00 |
| People in the field (input) | 2 |
| Billable days a year (input) | 220 |
| Target margin % (input) | 35% |
| Jobs a week (input) | 4 |
| Hours on the job (input) | 2.5 |
| Loaded labour rate (per hour) | $32.50 |
| Crew-hours | 5 |
| Labour cost | $162.50 |
| Overhead per sellable hour | $5.00 |
| Overhead share | $25.00 |
| Break-even cost | $202.50 |
| Price to quote | $311.54 |
| Profit on the job | $109.04 |
| Price if you MARK UP instead | $273.38 |
| Margin you actually keep with markup | 25.93% |
| Lost per job by marking up | $38.16 |
| Lost per year by marking up | $7,938.00 |
Computed with the same formulas as the free calculators on this site. Change any input in the calculator above to see your own numbers.
Setup, fall protection, plant protection and pack-up take about the same time on a small roof as on a large one. A small porch or garage roof priced purely per square foot would not cover them. Quote whichever is higher: the per-sq-ft price or the minimum.
An hourly view helps here too. With two people, loaded labour is 2 × $32.50 = $65 an hour and overhead is 2 × $5.00 = $10, so a crew hour costs $75 before chemicals. At 35% margin that is $75 ÷ 0.65 = $115.38 per crew hour. Every hour of setup you forget to count is $115.38 you do not bill.
The common mistakes: floor area, one-person pricing and markup
The three errors that sink a roof quote are measuring the wrong area, pricing a two-person job as if one person did it, and adding margin as markup.
- Floor area instead of roof area. As the 3,000 sq ft example shows, living area can overstate or understate the roof. Use footprint × pitch factor.
- One person's hours. If a second person holds ladders or works the ground, their hours are labour too. Set Workers to 2 in the calculator.
- Markup instead of margin. Adding 35% to the example break-even gives $459.00 and keeps only 25.93%. Dividing by 0.65 gives $523.08. The gap is $64.08 on one roof, or $13,328.00 a year at four roofs a week.
The wage error is the fourth: a $25 wage with 30% burden costs $32.50 an hour. The labour burden guide builds that percentage line by line, and the markup vs margin guide has the full conversion chart.
Excel formulas for a roof cleaning pricing calculator
A spreadsheet version takes ten inputs. The formulas below use this layout: B2 = footprint sq ft, B3 = pitch rise (inches per 12), B4 = production rate, B5 = people, B6 = wage, B7 = burden %, B8 = chemicals, B9 = yearly overhead, B10 = billable days, B11 = target margin %, B12 = minimum charge.
Pitch factor
=SQRT(1+(B3/12)^2)B3 = rise in inches per 12 inches of run. 6 returns 1.118.
Roof area
=B2*SQRT(1+(B3/12)^2)B2 = footprint including overhangs.
Break-even
=B2*SQRT(1+(B3/12)^2)/B4*B5*(B6*(1+B7)+B9/(B5*B10*8))+B8Crew hours × (loaded rate + overhead per sellable hour) + chemicals. B7 as a percent (30%). Overhead is divided over all people in the field.
Price to quote, with minimum
=MAX((B2*SQRT(1+(B3/12)^2)/B4*B5*(B6*(1+B7)+B9/(B5*B10*8))+B8)/(1-B11),B12)Break-even ÷ (1 − margin), never below the roof minimum in B12.
If you would rather not build and test it, the Pressure Washing Pricing Calculator ($39 one-time, Excel and Google Sheets) costs SH and surfactant on every job, shows your break-even before you quote, and has an "Am I underpricing?" check: type the price you had in mind and it answers in dollars. Its market check uses published per-sq-ft bands for driveways and house washes, not roofs, so on a roof you rely on the cost-up price.
Roof cleaning pricing calculator, app or spreadsheet?
Use whichever tool makes you enter your crew hours, chemical cost and overhead before it shows a price.
| Option | Cost | Suits | Watch for |
|---|---|---|---|
| National per-sq-ft range | Free | A sanity check | Built on someone else's crew, chemicals and roofs |
| Free pressure washing calculator | Free, no signup | One quote at a time | It takes hours on site, so convert roof area to hours first |
| Field-service app | Monthly subscription | Scheduling, invoicing, crews | Price lines only as good as the rates you enter |
| Spreadsheet template | $39 one-time | Owner-operators who want to see the math | You keep your chemical prices current |
Starting from nothing? The free Job Pricing Starter is one sheet covering loaded labour cost, overhead, break-even and the price to quote, and shows what markup pricing costs you. For roofing trades pricing replacement rather than cleaning, see the roofing estimate template guide.
What to put on your roof soft wash price sheet
A roof price sheet is a short table of your own numbers that turns a footprint and a pitch into a price in a minute.
- Pitch factor table from 4/12 to 12/12, worked out once with the formula above.
- Door-to-door production rate by roof type: low-slope, walkable, steep, cut-up.
- Crew size by roof type, since a second person doubles the labour hours.
- Chemical cost per 1,000 sq ft from your own concentrate usage and supplier price.
- Loaded labour rate and overhead per sellable hour.
- Target margin, applied by division.
- Roof minimum, calculated like the $311.54 example, not rounded down.
- Add-ons: gutter faces, skylights, a house wash on the same visit, each as minutes plus product.
Reprice the sheet when SH, fuel or wages move. A sheet built on last year's chemical price quietly lowers your margin on every roof.
Step-by-step: Soft Washing Roof Price: How to Work Out What to Charge for a Roof
- Measure the footprint. Measure length × width of the house from the ground, including overhangs. Note the pitch as rise in inches per 12 inches.
- Convert to roof area. Multiply footprint by the pitch factor √(1 + (rise ÷ 12)²). A 6/12 roof is 1.118, so 2,000 sq ft becomes 2,236 sq ft.
- Turn area into hours. Divide roof area by your door-to-door production rate, which includes setup, plant protection, dwell, rinse and pack-up.
- Cost labour for the whole crew. Multiply hours × people × wage × (1 + burden %). Two people at a $25 wage and 30% burden cost $65 an hour.
- Add chemicals and overhead. Add SH and surfactant used on this roof, plus crew hours × overhead per sellable hour. The total is break-even.
- Divide by one minus margin. Price = break-even ÷ (1 − margin), then quote the higher of that price and your roof minimum.
Skip the setup: Pressure Washing Pricing Calculator
The spreadsheet version of this guide for Excel & Google Sheets: type your numbers into the highlighted cells and the formulas do the rest. One-time $39, no subscription, instant download.
See the Pressure Washing Pricing Calculator →Buy now — $39Instant access by email after checkout via Payhip. Want to try the maths first? Use the free calculator — no signup.
Frequently asked questions
How much should I charge to soft wash a roof?
Charge break-even divided by one minus your margin. Measure footprint × pitch factor for roof area, convert to crew hours with your door-to-door rate, and add loaded labour, SH and surfactant and overhead. In this page's example a 2,236 sq ft roof comes to $523.08 at a 35% margin, using assumed inputs.
How do you calculate roof square footage for soft washing?
Multiply the footprint, including overhangs, by the pitch factor √(1 + (rise ÷ 12)²). A 6/12 roof has a factor of 1.118, so a 2,000 sq ft footprint is 2,236 sq ft of roof. Apply separate factors where roof planes have different pitches.
How much is it to soft wash a 2,500 sq ft roof?
It depends on your hours, crew and chemicals, not the area alone. Convert 2,500 sq ft to hours with your door-to-door production rate, cost the crew at the loaded rate, add SH, surfactant and overhead, and divide by one minus your margin. The calculator on this page does that arithmetic.
How do you price soft washing jobs?
Price soft washing from cost up: area, then hours at your production rate, then loaded labour for everyone on site, chemicals used on the job and an overhead share. That is break-even. Divide by one minus your target margin and compare with your minimum charge, quoting the higher number.
How often should a roof be soft washed?
There is no single interval; regrowth depends on climate, shade and roofing material, so follow the roofing manufacturer's guidance. For pricing, treat a repeat clean as its own job. If the roof has less growth, your chemical line and hours may fall, and the price should be recalculated from those inputs.
Is soft washing a roof worth it for a pressure washing business?
It is worth it when the price clears your break-even at a margin you can sustain. If a roof needs more setup or a second person, cost every one of those crew hours. Compare your roof price per crew hour with your house-wash work and keep whichever pays more for the time.
Should roof soft washing be priced per square foot or per job?
Quote the customer a price per job, and use price per square foot as a check. The per-job price comes from roof area, crew hours, chemicals and overhead. Dividing it by roof area gives your per-sq-ft figure, which you can compare across roofs to spot a quote that looks off.
I'm not a contractor, landlord or accountant. I build the pricing maths, and every number on this page shows its working so you can check it instead of trusting it. Watch the breakdowns on YouTube →