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What Goes on a Startup Pressure Washing Trailer: A Full Build Walkthrough

Tim Cray 4 min read

Key takeaways

  • Start with the machine you will not replace. An 8 GPM Honda GX690 gear drive is more than a first-year business needs, and that is the point.
  • Three 100 gallon slim tanks plus a 7 gallon soap tank. The front two are tied into a 200 gallon buffer that baffles sloshing, the rear is bleach, all in stainless brackets bolted to plates.
  • Three 18 inch aluminum reels on quarter-inch stainless mounts. 200 ft of 1/2 inch soft wash hose, 200 ft of FierceJet pressure hose, and a ball valve swivel to cut hand fatigue.
  • Build in the growth now. A plugged second port on the 11 gallon fuel tank and open rear deck space mean no re-plumb when a second machine arrives.
  • Keep it simple on a 3,500 lb Big Tex. A short tongue fits a garage, and a Hudson float valve on the fill means you stop babysitting the tank.
In this guide
What Goes on a Startup Pressure Washing Trailer: A Full Build Walkthrough - Expert Power Wash

One of the hardest questions for someone starting a pressure washing business is not "what does a rig cost" — it is "what actually needs to be on it." So here is a real one, component by component. This trailer went out to a contractor who had just started his business and needed something he could tow with his truck and store in the garage when he was not using it, so it would not tie up a vehicle.

The machine

An 8 GPM Honda GX690 gear drive unit. This is the machine we point people at when they intend to grow, and it is deliberately more machine than a first-year business strictly needs — because it is also the one you will not be replacing in two years. Gear drive slows the pump down and isolates it from engine vibration, which is what makes a machine survive daily commercial use.

Power and fuel

  • 24 DC marine-grade battery — built to be run down and recharged repeatedly, which is exactly what a 12V soft wash pump does.
  • 11 gallon fuel tank, expandable. There is a plugged port on it so a second machine can be fed from the same tank later. That plug is the whole point: it is a $0 decision at build time that saves a re-plumb when the business grows.

Tanks

Three 100 gallon slim tanks plus a 7 gallon soap tank:

  • The front two tanks are tied together into a single 200 gallon buffer. Tying them rather than running one large tank does something people do not expect — the two tanks baffle the water against each other and noticeably reduce sloshing on the road.
  • The rear tank is the bleach tank.
  • The 7 gallon soap tank sits on a custom mount.

All three sit in custom-made stainless steel tank brackets. Look underneath and you will see plates on each side that the brackets bolt to, with a full bracket system behind them — not a single bolt through the deck. Tanks working loose over time under the weight of liquid is one of the biggest failure points in this industry, and a mounting plate is far more stable than the typical setup.

Reels and hose

The reel mounts are quarter-inch stainless steel, not aluminum. That is a place it would have been easy to cut a corner and we did not.

The soft wash side

A 7 GPM 100 PSI soft wash pump feeding a Pro Mixer XL with a rinse valve, so the mix ratio is set at the mixer rather than batched in the tank. If that means nothing to you yet, start with how a soft wash mixing system actually works.

The detail nobody asks about but everybody appreciates

The garden fill runs through the reel and up into the tank, into a Hudson float valve. When the tank fills, it shuts off by itself. You hook up at the customer's spigot and stop thinking about it instead of watching a tank and walking back to turn off a tap.

The trailer itself

A Big Tex with a 3,500 lb axle. We have used these for years — they are built stout. This one has a shorter tongue, which makes it easier to pull and cuts the overall length, which matters a great deal when the plan is to park it in a garage.

Why this is the right shape for a startup

There is a lot of open deck space at the back for a second machine, a surface cleaner, or a toolbox as the business grows. Nothing on it is exotic. It is simple to work off, simple to maintain, and it is not overly complex — which matters more than it sounds when you are learning the trade and troubleshooting on a customer's driveway.

If we were starting out again, this is close to exactly what we would run.

Next steps

See the startup package guide for what to buy in what order, or skid vs trailer vs van if you have not settled that question yet. Browse our builds and rigs that are ready now.

Financing is available through several partners, so most first-time buyers finance the build and pay for it out of the work it does rather than draining their working capital — see financing. Or book a free discovery call and we will spec one around the work you plan to bid.

Frequently asked questions

What size pressure washer should a startup pressure washing trailer have?
This build runs an 8 GPM Honda GX690 gear drive unit. It is deliberately more machine than a first-year business strictly needs, because it is also the one you will not be replacing in two years. Gear drive slows the pump down and isolates it from engine vibration, which is what makes a machine survive daily commercial use.
How many water tanks does a pressure washing trailer need?
This trailer carries three 100 gallon slim tanks plus a 7 gallon soap tank. The front two are tied together into a single 200 gallon buffer, and the rear tank is the bleach tank. Tying two tanks instead of running one large tank baffles the water against itself and noticeably reduces sloshing on the road.
How should water tanks be mounted on a pressure washing trailer?
In custom stainless steel tank brackets that bolt to plates on each side of the deck with a full bracket system behind them, not a single bolt through the deck. Tanks working loose over time under the weight of liquid is one of the biggest failure points in this industry, and a mounting plate is far more stable than the typical setup.
What hose reels and hose go on a startup pressure washing trailer?
Three 18 inch full-frame aluminum reels with stainless steel manifolds, on quarter-inch stainless steel mounts rather than aluminum. The cam reel carries 200 ft of 1/2 inch soft wash hose, and there is 200 ft of FierceJet pressure washing hose. A ball valve swivel on the pressure side is an add-on option worth having because it cuts hand fatigue noticeably over a full day.
What soft wash system goes on a pressure washing trailer?
A 7 GPM 100 PSI soft wash pump feeding a Pro Mixer XL with a rinse valve, so the mix ratio is set at the mixer rather than batched in the tank. It runs off a 24 DC marine-grade battery, which is built to be run down and recharged repeatedly, exactly what a 12V soft wash pump does.
What does a float valve do on a pressure washing water tank?
The garden fill runs through the reel and up into the tank into a Hudson float valve, and when the tank fills it shuts off by itself. You hook up at the customer's spigot and stop thinking about it instead of watching a tank and walking back to turn off a tap.
What trailer is best for a small pressure washing setup?
This build is on a Big Tex with a 3,500 lb axle; we have used these for years and they are built stout. This one has a shorter tongue, which makes it easier to pull and cuts the overall length, which matters a great deal when the plan is to park it in a garage. There is open deck space at the back for a second machine, a surface cleaner or a toolbox as the business grows.
Written by

Tim Cray

Owner, Expert Power Wash

Tim and Kristina ran their own pressure washing company for more than ten years on trailers, box trucks, flatbeds, vans and skids before Expert Power Wash started building equipment for other contractors. Today EPW has 300-plus builds working in the field and services pressure washing rigs in the Oregon City shop every day.

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