Summary

Pressure washing looks like a simple cash job — fire up the petrol washer, blast the moss off, walk away with £200. In practice the cheapest jobs lose money because the operator forgot to factor in: setup and packup (40 minutes round trip), waste water containment if biocide is being used, kiln-dried sand for the block paving re-sand (which the customer expects but most pricing forgets), and the difference between a £400 entry-level electric washer that won't handle a 60m² drive in a morning and a £2,500 commercial petrol unit with a surface cleaner that will.

There's also a regulatory angle most one-man-band operators miss. Pressure-washed run-off carrying detergents or biocides cannot be discharged to surface water drains (the road gully). That's a Water Resources Act 1991 offence and the Environment Agency has fined contractors for it. Plain water rinse is usually acceptable, but as soon as you add a chemical treatment you are responsible for containing or directing run-off appropriately — to foul drain (with permission), to soakaway, or to a vac-pump waste tank.

This guide covers the variables, the kit, the regulations, and how to build a profitable pressure-washing price without underquoting or overquoting.

Key Facts

Quick Reference Table

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Job Area Throughput Typical price (2026)
Minimum call-out (small patio/path) <25m² 1–2 hrs £120–£180
Small patio clean (no re-sand) 15–25m² 1.5 hrs £130–£220
Medium patio clean + biocide 30–50m² 2–3 hrs £200–£380
Large patio clean + biocide + sealer 50–80m² 4–6 hrs £400–£750
Small block driveway clean + re-sand 30–40m² 2–3 hrs £220–£380
Standard block driveway clean + re-sand + biocide 50–60m² 3–4 hrs £300–£550
Large block driveway clean + re-sand + biocide 80–120m² 5–7 hrs £500–£900
Decking clean + re-stain (softwood) 20–30m² 1 day £250–£500
Roof tile soft-wash (specialist, separate quote) n/a n/a see roof cleaning pricing guide
Surface Max pressure Tip Approach
Concrete (poured/precast) 200+ bar 15° or surface cleaner Standard rotary
Block paving 180–200 bar Surface cleaner Pass slowly, re-sand after
Brick paving 180 bar 25° fan Test before; soft brick can pit
Indian sandstone ≤130 bar 40° fan, 300mm distance Low-pressure + biocide
Limestone ≤100 bar Fan tip only Biocide first, rinse low
Slate paving ≤130 bar Fan tip Cold water; avoid sealants
Softwood decking ≤120 bar Fan tip, with grain Re-stain/oil after
Composite decking ≤120 bar (check spec) Fan tip Mild detergent, rinse low
Render ≤80 bar Fan tip Avoid if loose; just biocide
Tarmac ≤50 bar (rinse only) Wide fan NEVER high-pressure
Resin-bound ≤100 bar Fan tip Cold rinse only

Detailed Guidance

What drives the price

  1. Area (m²) — base unit
  2. Surface type — block paving needs re-sanding (extra time + materials); Indian stone needs gentler pressure (slower throughput); composite decking needs manufacturer-compliant pressure
  3. Access — front driveway = easy; rear garden patio with narrow side gate = 20–40% premium for hauling kit + waste hose runs
  4. Water supply — customer outside tap available and flowing? If not, you need a bowser or tank (extra cost)
  5. Drain access — where does the run-off go? If chemical treatment used, you cannot send it to road gully
  6. Add-ons — biocide/algicide (extra £40–£80), sealer (extra £150–£300 on 50m²), re-sand (extra £35–£75)
  7. Minimum call-out — never under £120; setup/packup eats small-job profit

Cold vs hot water — when does it matter

For 90% of UK driveway and patio jobs, cold water at 200 bar with surface cleaner is fine. Hot water (60–80°C) matters when:

Hot-water washers cost 2–3× cold and need diesel for the burner. Justify the kit on commercial work, not domestic driveways.

Block paving — the re-sand step that gets forgotten

When you pressure-wash block paving, the kiln-dried jointing sand between blocks is washed out. Without re-sanding, blocks rock, weeds re-establish through the open joints within 6 weeks, and the customer rings to complain. Every block-paving clean quote MUST include:

  1. Clean (pressure wash)
  2. Allow surface to dry (24 hrs minimum)
  3. Brush in fresh kiln-dried sand
  4. Vibrate or sweep in
  5. Apply biocide before sand if heavy moss

Re-sand cost: ~£6–£14 per 25kg bag × 1 bag per 10–15m². For a 50m² drive that's 4 bags = £40–£55 in sand alone, plus 30 minutes brushing.

Waste water and environmental regulations

UK environmental law (Water Resources Act 1991, Environmental Permitting Regulations 2016) makes it an offence to allow polluting matter to enter controlled waters — that includes surface water drains, which discharge to rivers untreated. Environment Agency guidance (PPG13, GPP13) is clear:

In practice for domestic driveway work:

Fines for surface-water pollution can reach £20,000 in magistrates' court or unlimited in Crown Court. Don't gamble.

Damage risks and customer expectations

The big damage risks on a pressure-wash job:

Always brief the customer:

Pricing breakdown for a typical job

A typical 60m² block-paving driveway, front of house, normal access, including biocide and re-sand:

Item Cost
Petrol surface cleaner pass (60m² ÷ 25m²/hr) ≈ 2.5 hrs —
Setup, packup, hose run 0.75 hr
Total labour 3.25 hrs @ £55/hr £180
Petrol for washer (1 tank) £8
Biocide 5L (covers 100m²+) £45
Kiln-dried sand 5 × 25kg bags £55
Travel & setup overhead £35
Subtotal £323
Markup at 25% £81
Total to customer £404

Round to £400. Compare against rough rule of £6/m² × 60m² = £360 — close enough. Add £75–£150 for sealer if upsold.

Frequently Asked Questions

Do I need a waste carrier licence for pressure washing?

If you only pressure-wash on the customer's site and run-off stays on their property (e.g. drains to their soakaway or front garden), no. If you collect waste water in a vac-pump tank and transport it for disposal, yes — you need at least a lower-tier Waste Carrier registration with the Environment Agency. Lower tier is free, upper tier is £154 (renewable every 3 years).

Can I use any biocide off the shelf?

For algae/moss on hard landscaping, sodium hypochlorite (bleach-based) or benzalkonium chloride (quaternary ammonium) are the common active ingredients. Use professional-grade products that are HSE COSHH-assessed for outdoor use (not bathroom bleach). Always rinse plant beds adjacent to treated areas — biocide drift kills shrubs. Wear PPE (gloves, goggles, mask) per COSHH 2002.

Can I pressure-wash a render or painted wall?

You can, but at much lower pressure (≤80 bar, fan tip, 300mm+ distance). High pressure blows render off in patches and strips paint. For algae on walls, soft-wash with biocide spray (no pressure) is the professional approach. For pricing context see render repair pricing guide.

Should I always apply sealer after cleaning?

No — sealer is an upsell, not a default. Sealers extend the time between cleans by 6–24 months, repel oil and water, and enrich colour. But they need re-application every 2–4 years, can go cloudy if applied wrong or on damp surface, and add £150–£400 to a job. Offer it as optional; explain pros and cons; let the customer decide.

What's the minimum I should charge?

Domestic minimum call-out is £120–£180 in 2026. Below that the setup/packup/travel/fuel eats the profit and a 20m² patio just isn't worth a separate van visit. Bundle small jobs into one street-run if you can, or politely decline.

Regulations & Standards