Consumables
Choosing a detergent
Most people buy more pressure when what they needed was the right chemistry and four minutes of patience.
The detergent is the cheapest part of the job and the one that changes the result most.
The families that matter
Stone and terrace cleaners are alkaline and work on organic growth. Vehicle shampoos are pH-neutral and lubricating, so grit slides off rather than being dragged across paint. Upholstery solutions go in an extraction machine, never in a pressure washer. Mixing them up is how people strip a wax coat or foam a recovery tank.
Never in a pressure washer
Bleach, solvents, thinners, acids not sold for the purpose, and anything petroleum-based. They attack the seals and the pump, and they are outside every warranty.
How to apply
Bottom up, rinse top down. Applied top down, the detergent runs over dry dirt and leaves clean streaks that show through the final rinse. Never let it dry on the surface — on a hot day that means working in sections.
Concentrates and the real cost
Compare on dilution, not on bottle price. A concentrate at 1:20 is often a third of the cost per liter used of a ready-to-use bottle, and it is a fraction of the plastic.
Which washer does your job need?
- You wash cars
- A pH-neutral car shampoo, because harsher products strip wax and attack trim.
- You clean patios
- A product intended for the material, since some attack stone and grout.
- Your detergent will not draw
- That is the nozzle, not the product; detergent draws only at low pressure.
- You clean near plants
- Read the label for what runoff does, because plants and drains are downstream of everything you spray.
Picking by the surface
Vehicles
Where a pH-neutral product and a foam applicator do more than pressure, and where the wrong product damages trim.
Patios and stone
Where dwell time does the work and where the wrong chemical can etch or discolour the surface permanently.
Wood and decking
Where dedicated products exist and where general cleaners can grey or lift the fibers.
General grime
Where a general-purpose detergent and patience beat cranking up the pressure.
What to measure, and what to ignore
- Matching the product to the surface
- Stone, wood, paint and plastic have different tolerances. A product intended for one can permanently mark another.
- Dilution
- Concentrates need diluting correctly. Too strong risks damage; too weak does nothing and wastes the trip.
- Whether your machine can use it
- Some machines take only their own detergent cartridges. Using anything else may void a warranty or clog the system.
- Runoff and the environment
- Everything you spray goes somewhere: onto plants, into drains, into a soakaway. The label states what is acceptable.
- Dwell time
- Most detergents need to sit before rinsing. Applying and immediately rinsing wastes the product entirely.
Which figure for which surface
| What you clean | The product | The caution |
|---|---|---|
| A car | pH-neutral shampoo | Harsh products strip wax |
| Stone patio | A product for that stone | Some etch or discolour |
| Decking | A dedicated wood cleaner | General cleaners can grey wood |
| Anywhere near plants | Check the label | Runoff reaches roots and drains |
What to avoid doing
- Using household bleach or strong chemicals
- They can damage stone, harm plants and react badly with other products. Detergents made for the job exist for a reason.
- Rinsing immediately after applying
- Most detergents need dwell time to work. Rinsing at once wastes the product and leaves the dirt.
- Letting detergent dry on the surface
- On a hot day it dries and streaks or stains. Working in the shade and in sections avoids it.
- Ignoring runoff
- Everything sprayed ends up in soil or a drain. Plants downhill of a patio clean are the ones that suffer.
By how hard you will work it
- The car owner
- Uses a pH-neutral shampoo and a foam applicator, and never a general-purpose degreaser on paint.
- The patio owner
- Matches the product to the stone and gives it dwell time in the shade.
- The gardener
- Reads the label about runoff and rinses plants that get splashed.
Servicing, storage and working life
Detergent left in a machine's system dries and clogs the pickup, and a foam applicator that is not rinsed after use will be blocked next time. Running clean water through the detergent path after every session takes a minute and prevents the problem entirely.
- Draw clean water through the detergent system after use to flush it.
- Rinse foam applicators and bottles rather than storing them full.
- Store concentrates sealed and away from frost, which ruins some of them.
- Keep products in their original containers with their labels intact.
Safety
Chemicals, runoff and the surfaces around you.
- Read the label and wear the protection it specifies; some concentrates are harsh on skin and eyes.
- Never mix products; some combinations produce dangerous fumes.
- Wet plants before and after cleaning nearby so runoff is diluted.
- Keep concentrates locked away from children and pets.
The questions we hear
Can I use washing-up liquid?
It will not damage most machines in the short term, and it will not do the job either — it has no dwell, no alkalinity and it foams badly in the detergent circuit. The bigger risk is household bleach and anything solvent-based: those attack pump seals and the damage is not covered.
Why does dwell time matter more than pressure?
Because chemistry works on a clock. On a green, algae-stained slab, a stone cleaner left for four minutes then rinsed removes what fifteen extra bar will not. Dwell also lets you clean at a lower pressure, which is how soft surfaces survive.
Why is my detergent not coming out?
Detergent only draws at low pressure. With a high-pressure nozzle fitted, nothing will come through however full the bottle is.
How long should detergent dwell?
Long enough to work but not long enough to dry, which the label will specify. Working in the shade makes that far easier.
Will detergent harm my plants?
It can, and everything you spray runs somewhere. Wetting plants before and after dilutes what reaches them.
Must I use the maker's own detergent?
Some machines with cartridge systems effectively require it. On others, any suitable product works, but check the manual first.
Can one detergent do everything?
A general-purpose product covers a lot, but cars, stone and wood have different needs and using the wrong one can mark a surface permanently.
How should I store detergent over winter?
Sealed, in its original container and away from frost, which ruins some products outright. A concentrate that has frozen may separate and never mix properly again.
What this page is based on
The washers above come from the catalog of this site. Specifications are those the manufacturer and the Amazon page publish; prices are what Keepa reported for the date below, and both move. The order follows declared specifications, stated strengths weighed against stated limits, and price. No machine here has been put to work by us, and nothing on this page pretends otherwise.
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