Pressure Washing Pricing Guide: Square Feet, Mix, Minimums

Short answer: This pressure washing pricing guide prices flat work by the square foot — driveways, patios, decks, roof planes, commercial lots — and sells siding as a flat price per house instead. The square-foot number buys wand time only. Setup, travel, chemical at 1 to 2 percent sodium hypochlorite for a house wash, water hauling when there is no spigot, and dwell time all sit outside it, which is why a minimum charge has to cover the stop before any area is measured.

Two driveways with the same tape measurement can be a ninety-minute stop or a full afternoon, and the square-foot number on your price list says nothing about which one you agreed to do. The unit measures area while the job consumes chemistry, water, dwell time, and setup. This page takes the unit apart and runs the same 1,200 square feet twice.

Which unit does each surface actually price in?

Not everything belongs in square feet, and forcing it there is where the first losses happen.

Surface	Unit that holds	What really sets the hours
Driveway, sidewalk, patio, pool deck	Square feet of flatwork	Surface cleaner width, pass count, staining
House siding	Flat price per house, banded by stories and footprint	Elevation count, landscaping to cover, dwell and rinse
Wood or composite deck	Square feet of walking surface; railing priced separately by linear foot	Spindle count, stripping versus washing, species
Roof	Square feet of roof plane, never floor footprint	Pitch, access, gutter protection, mix strength
Commercial lot	Square feet, usually inside a night window	Reclaim requirement, gum removal by count, drive lanes versus stalls

Siding is the one people fight hardest to keep in square feet, and it fits worst. Wall area on a two-story colonial rises with the second floor while your ground time barely moves, so the rate that pays on a ranch overcharges the colonial and undercharges a rambling one-story with nine elevations and a screened porch. Band it by story count, rough footprint, and a named list of what is included.

What is inside the square-foot number and what is not?

The unit price covers the passes you make and the fuel and wear that go with them. Everything below is a separate decision, written down before the job starts.

• Who supplies the water. A usable spigot with real flow is an assumption, not a fact.
• Where the wash water goes. The street, a lawn, or a vacuum and a tote.
• What counts as clean. Uniform, or every stain gone. Those are different jobs.
• Which stains are excluded. Oil, rust, tire marks, paint drips, and battery acid are chemistry lines, not area lines.
• Who moves the cars, furniture, and grills.
• Post-treatment. A surface left with a residual biocide stays clean longer and costs more today.

Why does the surface pick the method before it picks the price?

Because the wrong method does not produce a slower job. It produces a claim.

Surface	Method	Reason
Broom-finish concrete, pavers	High pressure with a surface cleaner	Dense and tolerant; area coverage is the whole point
Vinyl, aluminum, stucco, painted wood	Soft wash	Pressure drives water behind cladding and lifts paint
Asphalt shingles	Soft wash only	Pressure strips granules and voids roof warranties
Cedar, redwood, composite decking	Low pressure plus chemistry	Grain fuzzes; the cap layer on composite scars permanently
Brick and older mortar	Low pressure plus chemistry	Soft joints blow out and repointing is not your line

Soft wash is the more profitable method and the slower one on the clock. The cleaning is done by concentration and dwell, not by the gun, so a house wash is apply, wait, rinse, inspect. A wand-hours mental model applied to a soft wash job produces a number that runs out halfway through the dwell.

Put the method in writing, with the surface named. A line reading vinyl siding, soft wash at low pressure, no high-pressure application to cladding is what stands between you and a homeowner who wanted the pressure turned up.

How do I cost the chemical instead of guessing it?

One formula covers every batch you will ever mix:

gallons of stock = target percent × total gallons of mix ÷ stock percent

Professional sodium hypochlorite ships around 10 to 12.5 percent. Thirty gallons of 2 percent mix from 12.5 percent stock is 30 × 2 ÷ 12.5 = 4.8 gallons of stock, the rest water, plus surfactant at roughly 1 percent of batch volume.

Application	Common target strength
Vinyl, paint, wood, windows	1 to 2 percent
Stucco, concrete, brick, gutters	2 to 4 percent
Asphalt roofs and heavy organic growth	3 to 6 percent

Two consequences fall out of that table. A downstream injector draws roughly one part chemical to ten parts water, which caps effective strength near the low end of the roof range — roof work generally needs a 12-volt batch system, and that is a capital line, not a mix line. And sodium hypochlorite loses strength on the shelf, so a drum bought at 12.5 percent and used six weeks later is not 12.5 percent. Cost the mix from what you poured, not from the label, and keep the supply tickets where you can find them, the habit described in contractor receipt organizer.

What breaks the square-foot unit?

Seven conditions. None of them show up in a measurement.

• No usable water. A buffer tank, a fill stop, and the drive time to get there. On a rural property this alone can add an hour before you spray anything.
• Distance from the truck. Two hundred feet of hose uphill is a setup cost and a pressure loss at the same time.
• Substrate age and porosity. Old, open-pore concrete holds growth in the surface and takes a second pass at the same area.
• Stain class. Oil needs a degreaser with dwell and often heat. Rust needs an oxalic or similar acid treatment, applied and neutralized. Both are priced by the stain, by the hour, or by the square foot of the stain itself.
• Height. Second and third stories mean an extension wand, a ladder, or a longer x-jet reach, and every one of those slows the rinse.
• Runoff rules. Where the local stormwater program restricts what enters a storm drain, capture and disposal become a line on the estimate. The federal framework is EPA’s NPDES stormwater program and the enforcement is local, so read your own municipality’s rules once and price accordingly.
• The tool in your hand. A 20-inch surface cleaner and a zero-degree tip cover the same area with a three-to-one difference in time. Quote what you will actually use.

What does the same 1,200 square feet cost in two conditions?

Two driveways, both measured at 1,200 square feet. All rates below are placeholders — put your own in.

Driveway A — six years old, broom finish, light algae film, working spigot at the front of the house, truck parked at the curb thirty feet away, runoff to the street permitted.

Driveway B — eighteen years old, heavy black growth in an open surface, a 40-square-foot oil stain at the apron, rust runs under two downspouts, no working spigot so the tank gets filled en route, truck parked 180 feet away up a grade, and wash water has to be kept out of the storm drain at the low end.

On the clock	A	B
Travel and stage	0.4	0.4
Hose run and setup	0.3	0.7
Fill the buffer tank	—	0.5
Pre-treat and dwell	0.2	0.6
Surface cleaner passes	0.7	1.4 (two passes)
Degrease the oil stain	—	0.5
Oxalic treatment and neutralize	—	0.6
Edge and detail wand	0.3	0.5
Contain, vacuum, and transfer runoff	—	0.8
Rinse, break down, load	0.4	0.6
Total hours	2.3	6.6

Convert with your own rates. At a placeholder burdened labor cost of $38 an hour plus $14 an hour of overhead, the clock runs at $52.

	A	B
Labor and overhead	$120	$343
Chemical — 4 gal of 2% mix vs 12 gal of 4% plus degreaser and oxalic	$14	$76
Fuel, wear, tank haul, vacuum	$12	$30
Captured wash water disposal	—	$35
Cost	$146	$484
Price at a 35% target margin	146 ÷ 0.65 = $225	484 ÷ 0.65 = $745
Implied price per square foot	$0.19	$0.62

Three times the price on identical area, and the margin arithmetic in that second-to-last row is the part people get wrong. Adding 35 percent markup to Driveway B gives $653, which is a 26 percent margin and $92 short of what a 35 percent margin actually requires. Markup is added to cost; margin is taken out of price. Divide by one minus the margin.

Why does every small job need a minimum charge?

Because the fixed part of a stop does not shrink with the area. On Driveway A the travel, hose run, and breakdown alone are 1.1 hours, which is $57 of clock before a drop of water moves, and closer to $70 once fuel and the drive back are in. A 400-square-foot patio priced at Driveway A’s $0.19 comes to $76 — a break-even stop that also costs you the slot a real job would have used.

Set the minimum from the fixed cost of a stop plus your margin, not from a competitor’s number, and say it on the phone before you drive anywhere. Add-on pricing is the honest way through: the patio at a real price when it rides along with the driveway, the minimum when it stands alone. Small residential tickets are also the ones that go unpaid most often, so take the card on site — the pattern is in how to get clients to pay.

Is a published price per square foot worth anything?

As a sanity check on your own arithmetic, and nothing more. The two figures above came out of one set of placeholder rates on one pair of driveways.

Per-square-foot numbers move with things that have nothing to do with the concrete in front of you. Sodium hypochlorite price tracks the chlor-alkali market and freight from the nearest plant. Water is metered in one town and free on a hydrant permit in the next. Reclaim is required on commercial work in some jurisdictions and nowhere in others. Cold markets compress the season into a few months, which changes what a single stop has to earn.

Treat a published range the way you treat a test patch: it tells you whether you are in the neighborhood. If your number lands at half or double what local work is going for, the error is almost always in your pass count, your dwell assumption, or a stain you have not priced separately.

What should I record once the trailer is loaded?

Three things, every time: actual hours against quoted hours, gallons of stock actually poured, and the receipt for every drum, tote, and gas fill. Two jobs where the pre-treat ran double is a mix problem or a dwell problem, and neither is visible without the record.

Keel is an iOS app built for doing that on a phone with wet hands. Everything stays on the device — no account, no bank connection, no cloud, no login, and an App Store privacy label reading Data Not Collected. Photograph the chemical supplier’s ticket, the fuel receipt, and the disposal slip, and Apple Intelligence reads them on device. Route driving between stops logs as mileage instead of evaporating, which matters in a trade that spends half its day towing; the deduction side is in how to track mileage for taxes. The invoice leaves the driveway with your own numbering, your logo, and a payment link the customer scans as a QR code. At year end the Accountant Pack exports a CSV plus a one-page summary PDF. Free is $0 with unlimited invoices, receipts, and mileage; Keel Pro is a one-time $249.99 Lifetime purchase rather than a subscription, and you can get it on the App Store. The write-offs behind those receipts sit in self-employed tax deductions.

Frequently asked questions

How do you price pressure washing per square foot?

Measure the flat surface, decide your method and pass count, estimate the hours including setup and dwell, multiply by your burdened hourly cost, add chemical and disposal, then divide by one minus your target margin. The resulting per-square-foot figure is an output of that calculation, not an input to it, and it changes with surface condition.

Should I charge by the square foot or by the hour?

Square feet for flatwork you can measure and predict, hourly or by the stain for anything you cannot. Oil, rust, paint overspray, and gum removal do not scale with area, so they belong on their own line. Siding is neither: band it as a flat price by story count and footprint, with the elevations listed.

Why is soft washing priced differently from pressure washing?

Soft washing does the cleaning with chemical concentration and dwell time rather than pressure, so the clock includes waiting. It also uses far more sodium hypochlorite per job, and roof work usually needs a 12-volt batch system instead of a downstream injector. The higher price reflects chemical volume, equipment, and the liability you are absorbing by not using pressure.

What should my minimum charge for pressure washing be?

Whatever the fixed cost of one stop is, plus your margin. Add travel there and back, hose run, setup, breakdown, and fuel, multiply by your hourly cost, then apply your margin. Most operators land on a figure that makes a single small patio or walkway uneconomical alone, which is the correct signal — bundle it or decline it.

Do I have to capture the water when I pressure wash?

It depends on the surface, the chemicals, and the local stormwater rules, and the answer differs between residential lawns and commercial lots draining to a storm inlet. Read your municipality’s requirements once, then price capture and disposal as a stated line when it applies. Assuming runoff is free is how a commercial bid loses money.

How much sodium hypochlorite do I need for a house wash?

Work from the target strength, not from habit. One to 2 percent suits vinyl, paint, and wood. Multiply the target percent by the total gallons you plan to mix, then divide by your stock strength to get gallons of concentrate. Stock loses potency on the shelf, so a six-week-old drum yields less than the label says.

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This article is general information, not professional or tax advice.