Pressure Washing Invoice Example: Surfaces, Chemistry, Minimums

Short answer: A pressure washing invoice example bills each surface separately because each surface takes a different method — concrete at 3,000 to 4,000 psi through a surface cleaner, vinyl siding and shingles by soft wash under 100 psi. The invoice below covers 940 sq ft of driveway, 2,180 sq ft of siding, and a 320 sq ft composite deck for $1,486, with setup, chemical, water haul, and wastewater capture on their own lines.

One machine, one trailer, one afternoon — and five different jobs, each with its own pressure, its own chemistry, and its own way of going wrong. A single “wash the house and driveway” line hides all of that, and it is also the line that leaves you holding a damage claim when a customer decides the deck should have come out brighter. Below is one finished invoice, why each line is separate, how the chemical number is actually calculated, and the six lines customers question. The field checklist that applies to any trade is in what to include on an invoice.

What does a finished pressure washing invoice look like?

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INVOICE

Invoice number	2026-0455
Service date	June 18, 2026
Due date	On receipt
Property	803 Harker Court
Quote reference	Q-2026-0441, accepted June 11, 2026

From Northline Exterior Cleaning LLC Ray Ostrander · ray@northlineclean.com · (555) 663-2077

Bill to Sandra Whitlock, 803 Harker Court

#	Description	Qty	Rate	Amount
1	Mobilization and setup — trailer staged, 250 ft of pressure hose and 200 ft of chemical line run, supply flow tested, plants pre-wet, garage threshold taped and dammed	1	$145.00	$145.00
2	Driveway and apron — 16 in surface cleaner at 4.0 gpm and 3,500 psi, edges wanded, post-treated to slow regrowth	940 sq ft	$0.22	$206.80
3	Oil stain treatment, 3 parking positions — alkaline degreaser, 15 min dwell, agitated, two passes. Improvement expected; complete removal not warranted on 19-year-old concrete	3 ea	$40.00	$120.00
4	Front walk and steps — includes 62 LF of wand-cut edge along the bed line	180 sq ft	$0.34	$61.20
5	House soft wash — 12.5% sodium hypochlorite cut to roughly 2% at the surface with surfactant, applied under 100 psi, 8 min dwell, rinsed top-down; landscape pre-wet and post-rinsed	2,180 sq ft	$0.17	$370.60
6	Rust removal, two hose-bib runoff stains on the north elevation — oxalic acid applied and neutralized separately from the wash	2 ea	$45.00	$90.00
7	Composite deck — deck-safe cleaner, rinsed at no more than 1,200 psi held 12 in off the board, per the decking manufacturer’s published limit	320 sq ft	$0.44	$140.80
8	Gutter face brightening — exterior faces only, gutter-specific cleaner hand-applied and rinsed. Interior trough cleanout not included	96 LF	$1.35	$129.60
9	Water supply — the exterior spigot delivers 4.1 gpm against a 4.0 gpm machine with no reserve; 325 gal buffer tank hauled and refilled once mid-job	1	$87.00	$87.00
10	Wastewater management — driveway runoff bermed at the street inlet, collected on a mat, vacuumed and hauled to an approved sanitary disposal point per the municipal stormwater rule	1	$135.00	$135.00
11	Minimum service charge — met by the scope above, no adjustment applied	1	$0.00	$0.00

Balance due	$1,486.00

Excluded — the roof (quoted separately as Q-2026-0448, soft wash only, no walking of the shingle field), window glass and screens, the interior gutter trough, and any surface previously coated with a product not rated for wet cleaning.

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Four numbers carry that invoice: 1,120 sq ft of flat concrete, 2,180 sq ft of siding, 320 sq ft of deck, and 96 LF of gutter face. A customer can walk the property with a tape and check every one. Rates here are one operator’s numbers in one market. Build your own the way pressure washing pricing guide sets out: time your machine on your surfaces, then work back to a square foot.

Why does each surface get its own line and its own method?

Because the method is not a preference. On the wrong surface, high pressure is damage, and damage is a claim rather than a callback.

Surface	Method	Working pressure	Chemistry at the surface
Concrete drive, walk, curb	Surface cleaner, then post-treat	3,000 to 4,000 psi	0.5 to 1% sodium hypochlorite
Vinyl, aluminum, fiber cement siding	Soft wash applied, rinse only	Under 100 psi applied	About 2% plus surfactant
Asphalt shingle roof	Soft wash, dwell, low-pressure rinse	Under 100 psi	3 to 4%, no scrubbing
Wood deck and fence	Fan tip, wood cleaner, then brightener	500 to 1,200 psi	Percarbonate or dilute hypochlorite
Composite deck	Cleaner and rinse to the board maker’s limit	Under 1,200 psi at 12 in	Deck-safe cleaner only
Brick, stucco, EIFS	Soft wash — pressure erodes mortar and blows out stucco	Under 500 psi	Mild, or a specialty product
Painted or coated anything	Test patch first, in writing	Whatever the patch survives	Test first

The roof line is the one that ends businesses. The Asphalt Roofing Manufacturers Association recommends a low-pressure bleach-and-water application dwelled and rinsed, and is explicit that a shingle should never be scrubbed or pressure washed, since either loosens granules — their guidance is published as Algae Discoloration of Roofs. A granule-stripped roof is a roof replacement, and your general liability carrier will read that bulletin before you do.

How is the chemical line actually calculated?

From the stock strength down to the target at the surface, which is one division.

Sodium hypochlorite is commonly sold to contractors at 12.5 percent. To land at 2 percent on siding: 2 ÷ 12.5 = 0.16, so one part stock to 5.25 parts water. In a 50 gallon batch that is 8 gallons of hypochlorite and 42 gallons of water, which checks back as 8 × 12.5 ÷ 50 = 2.0 percent.

Target at the surface	Stock per 50 gal batch	Typical use
0.5%	2 gal	Concrete post-treat
1%	4 gal	Light organic film, soffits
2%	8 gal	House wash on vinyl and fiber cement
3%	12 gal	Roof, moderate algae
4%	16 gal	Roof, heavy algae and lichen

Two things follow. Stock loses strength on the shelf and in heat, so a drum bought six weeks ago is not 12.5 percent anymore, and you either test it or you mix rich and waste product. And surfactant goes in at the label rate, not by eye — it is what makes the mix cling long enough to work on a vertical surface.

Then the humbling part. If stock costs you $2.40 a gallon delivered, the 8 gallons in that house wash is $19.20 plus surfactant. Chemistry is a rounding error on a $1,486 invoice. Setup, travel, water, and the operator’s day are the invoice.

Where does the minimum charge live, and how do I say it?

On the invoice as a visible line, even when it is not triggered — as line 11 does. A minimum that only appears on small jobs looks like a penalty. A minimum that appears on every invoice looks like a policy.

The arithmetic is simple and it is brutal. Every job carries fixed clock regardless of size: load-out, drive there, position the trailer, run hose, test the supply, pre-wet, tear down, coil, drive back, and invoice. Call that 2.4 hours on a property 22 minutes out. If your truck and operator cost $520 for a nine-hour clock, that fixed block is $139 before a single square foot is cleaned. Add one productive hour and you are at $196 of cost, which needs a price near $280 to hold a 30 percent margin.

A 240 sq ft patio at $0.22 is $53. That job does not lose a little money — it loses the entire afternoon it was scheduled in. Either it hits the minimum, or it gets scheduled on a street where you are already parked.

Why are water and wastewater billable lines?

Because both are constraints, and neither is free.

A 4.0 gpm machine wants 4.0 gallons every minute it is running, continuously. A residential hose bib that tests at 4.1 gpm has no reserve at all — one toilet flush inside and the pump starves. That is why the buffer tank exists: it is the machine’s supply, not a convenience, and the hauling and mid-job refill are real time. Say the measured flow on the line and the question stops.

Wastewater is the one with teeth. Wash water carrying detergent, oil, and organic matter is a non-stormwater discharge, and discharging it to a municipal storm drain without authorization runs into the Clean Water Act and the NPDES stormwater program. Many municipalities have their own explicit rule. The enforcement lands on the contractor, not the homeowner, which is exactly why the containment, the vacuum, and the disposal go on the invoice as work performed rather than disappearing into an overhead you are quietly absorbing.

Which lines does a customer question, and how should they read?

The line	What they mean	Write it like this
Setup, $145	”You charged me to unroll a hose.”	Name the contents: 250 ft of hose run, supply tested, plants pre-wet, threshold dammed
Water, $87	”You used my spigot.”	State the measured flow — 4.1 gpm against a 4.0 gpm machine leaves nothing in reserve, so the tank is the supply
Wastewater, $135	”The rain washes it away anyway.”	Point at the rule, and note that the citation lands on the contractor
Oil stains, $120	”They are still there.”	Put the limit on the line before the work, not after: improvement expected, complete removal not warranted on 19-year-old concrete
Deck at $0.44 vs siding at $0.17	”Why is the small deck more per foot?”	The deck is board-by-board hand work under a manufacturer’s pressure ceiling; the siding is applied, dwelled, and rinsed
Gutter faces, $129.60	”You washed the house — gutters are part of the house.”	Say what a house wash covers and does not cover in the same sentence: siding and soffit yes, oxidized gutter faces no, because that stain is a different chemistry

The pattern in every row is the same. Move the sentence you would have said at the door onto the line where the customer reads it before the argument starts.

What changed between the quote and the bill?

Three things move between a driveway walkthrough and a finished job, and all three belong on the page.

Measured quantities. A quote paced at 900 sq ft and taped at 940 should read “940 sq ft (quoted 900)”. A number that moves silently is a number that gets challenged.

Declined scope. The roof was quoted and not accepted. Leaving it off entirely invites “I thought that was included.” Carrying it on the exclusions line with its own quote number closes the question and keeps the sale alive.

Discovered work. The two rust stains were not visible until the siding was clean. They are their own line with their own chemistry, approved before they were treated, not folded into line 5. On a job billed the day it is finished, getting paid before you leave the street is most of how to get clients to pay.

What do I keep after the trailer is hooked up?

Photographs of every surface before and after, the disposal ticket, the fuel and chemical receipts, and the miles. The before-and-after set is not marketing — it is the evidence file when someone claims a stain that predates you.

Keel handles that from the truck. The invoice goes out before you pull off the street, with your own numbering, your logo, your brand color, and a payment link the customer scans as a QR code. The hypochlorite drum, the surfactant, the fuel, and the disposal fee get photographed and read on the device by Apple Intelligence: no account, no bank connection, no cloud, no login, and an App Store privacy label reading Data Not Collected. Every property on the route logs as mileage, and the rate that applies is in IRS mileage rate 2026. At year end the Accountant Pack exports a CSV and a one-page summary PDF, and the whole year leaves as a single file. Free is $0 with unlimited invoices, receipts, and mileage; Keel Pro is a one-time $249.99 Lifetime purchase rather than a subscription.

Frequently asked questions

What should a pressure washing invoice include?

Both names, the property address, a unique invoice number, service and due dates, and the accepted quote number. Then each surface on its own line with its measured quantity, the method and working pressure used, and the chemistry applied. Add setup, water supply, wastewater handling, your minimum charge line, and a short exclusions list naming anything quoted separately or declined.

How do you price a pressure washing job per square foot?

Measure each surface separately and give each its own rate, because a surface cleaner on concrete and a soft wash on siding are different production rates. Time your own machine over a known area to get square feet per hour, divide your loaded hourly cost by that figure, add chemical and overhead, then add margin. Published per-foot rates are a sanity check, nothing more.

Why is soft washing charged differently from pressure washing?

Because it is a chemical process rather than a mechanical one. Soft washing applies a dilute sodium hypochlorite and surfactant mix at under 100 psi, lets it dwell, then rinses. The cost sits in the chemistry, the dwell time, and the pre-wet and post-rinse of landscaping, not in machine hours, and it is the only safe method on vinyl siding and asphalt shingles.

Should I charge a minimum for small pressure washing jobs?

Yes, and show the line on every invoice so it reads as policy rather than punishment. Fixed clock — load-out, travel both ways, positioning, hose runs, supply testing, tear-down, and invoicing — runs a couple of hours regardless of job size. Any job that does not clear that cost plus margin should either take the minimum or be scheduled beside another job on the same street.

Can I let pressure washing runoff go into the storm drain?

Generally no. Wash water carrying detergent, oil, and organic matter is a non-stormwater discharge under the Clean Water Act, and many municipalities have their own explicit prohibition with fines attached to the contractor. Contain the runoff, collect it, and dispose of it as your jurisdiction directs. Bill the containment and disposal as a line rather than absorbing it.

How do I avoid a damage claim on a pressure washing job?

Write the method on the invoice line — the pressure used, the distance held, and the chemistry — so the record shows what was applied to what. Test-patch anything painted, coated, or unknown before committing, and state on the line where a stain may not fully release. Never take a wand to shingles, stucco, or old mortar.

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