How to Build a Professional Soft Wash System from Scratch

Building your own soft wash system is one of the best investments a contractor can make. You control the components, the quality, and the cost — and you end up with a rig built exactly for how you work. Here's a straightforward guide to getting it done right.

Step 1: Start with the Right Pump

Your pump is the heart of the system. For most soft wash applications, a 12V diaphragm pump in the 5–7 GPM range is the standard. Look for one with automatic pressure shut-off — it protects the pump when demand drops and extends its service life significantly. The AquaVanta Pro 12V 7 GPM Automatic Shut-Off Pump is built specifically for this application.

Step 2: Choose Your Tank

Most contractors run a 50–100 gallon poly tank depending on their trailer size and job volume. Make sure it's rated for chemical use — soft wash mixes are corrosive and will degrade standard tanks over time.

Step 3: Add a Proportioner

A proportioner lets you dial in your chemical mix ratio on the fly without pre-mixing in the tank. This saves chemical, reduces waste, and gives you flexibility across different job types — roofs, siding, concrete — without swapping tanks.

Step 4: Plumbing and Fittings

Use chemical-resistant fittings throughout. Ball valves at key points give you control over flow and make maintenance easier. Don't cut corners here — a fitting failure mid-job is a costly problem.

Step 5: Hose and Gun Setup

Soft wash hose needs to be rated for chemical exposure. Run enough length for your typical job — 200–300 feet is standard for most residential work. Pair it with a downstream gun and the appropriate nozzle for your application.

Step 6: Wiring and Power

Wire your 12V pump directly to a dedicated battery with an inline fuse. Keep connections clean and protected from moisture. A simple on/off switch at the operator position makes the system easy to run solo.

Step 7: Test Before You Go Live

Run clean water through the full system before your first job. Check every fitting, valve, and connection under pressure. Fix any drips before chemical ever touches the system.

Final Thought

A professional soft wash system doesn't have to be complicated — but it does have to be built right. Start with quality components, plan your layout before you build, and you'll have a rig that works hard and lasts.