How it works
Pressure, flow and heat.
PSI is impact: it breaks the bond between the soil and the surface. GPM is flow: it carries the mess away and covers ground. Heat matters more than either. Cold water moves grease around. Hot water dissolves it.
Hot water to 200 °F for oil, animal fat, cooking grease and diesel film
What it removes
Grease and oilRoad film and saltMud and clayAlgae and mildewDiesel sootManure and litterGum and graffitiChalking paint
Hot water, PSI + GPMRunoff contained, not drained
01Heat dissolves02Pressure breaks the bond03Flow carries it off
Typical working ranges
| Surface | Pressure | Water |
|---|---|---|
| Concrete, floors, dumpster pads | 2,500–4,000 PSI | Hot for grease |
| Heavy grease and oil | 3,500–4,500+ PSI | Hot, always |
| Fleet and trailers | 1,200–1,900 PSI | Hot with degreaser |
| Equipment frames and tracks | To 4,000 PSI | Hot |
| Building exteriors | 2,000–3,000 PSI | Varies |
| Vinyl siding | 1,300–2,000 PSI | Cold |
| Roofs, wood, painted surfaces | Soft wash — chemistry, not pressure | Cold |
Equipment-industry typical, not code. Every surface gets a test spot.
Right for
✓Fleet yards, trucks, trailers, heavy equipment
✓Warehouse floors, docks, dumpster pads, drains
✓Building exteriors, sidewalks, commercial property
✓Roofs and siding — soft wash only
Big coverageHot water for greaseAudit-readyWater contained
Wrong for
✕Rust or profileIt will not remove rust or mill scale, and leaves no coating profile. Not a substitute for abrasive prep.
✕Electrical and envelopeWater goes where you point it and keeps going — motors, bearings, panels, behind siding.
✕Soft masonry and woodHigh pressure raises wood grain and cuts mortar out of joints.
✕Sensitive colorSodium hypochlorite strips organic pigment. Test-spot reds, blues, greens and oranges.
✕Shingle roofs3,000 PSI on a shingle roof voids the warranty. ARMA calls for low-pressure detergent washing.
The facility holds the stormwater permit, not the contractor. Ask any bidder what they do with the water. If the answer is a shrug, that's your answer.
Standards & compliance
Wash water stays contained — detergent, oil and metals are a prohibited discharge.Clean Water Act §402
Containment mats, vacuum recovery, storm drain plugs.EPA vehicle-washing BMP
Sanitary sewer disposal needs prior approval.Local POTW authorization
The facility's stormwater permit is what is at risk.NPDES permit conditions
Typical jobs
- Weekly fleet washing on contract
- Warehouse floor and dock apron
- Kitchen grease and dumpster pads
- Equipment cleaned for resale or lease return
Questions we get
Do you contain the wash water?
Yes. Containment and recovery are planned before cleaning starts — mats past the wash area, vacuum recovery, storm drain plugs, and legal disposal.
Hot or cold water for grease?
Hot. Cold water relocates grease to the far end of the slab; hot water dissolves it.
Will it damage my roof or siding?
It can. Roofs, painted surfaces, wood and EIFS get soft washing — low pressure and chemistry — not high pressure.