Pressure washing for businesses: entrances, car parks and loading areas

Commercial pressure washing takes months of Brisbane weather off a building's approach in one evening. Shaded concrete grows mould through the wet season, foot traffic adds gum and drink stains, and tyres carry oil and grit up every car park ramp. Washed properly, with the pressure matched to the surface and the water managed, entrances, paths, car parks and loading areas look cared for again and stay that way for a season. Washed badly, the same job strips pavers, lifts paint and sends dirty water down a stormwater drain. This guide covers which surfaces need it, how often, and what to ask a contractor before you book.

Which surfaces need it

Building entrances and steps. The first thing a visitor sees, and the first place mould takes hold under an awning. Quarterly is typical.

Paths, ramps and covered walkways. Shaded sections grow green and black mould; uncovered sections collect grit. The shaded parts usually set the frequency.

Car parks, driveways and ramps. Oil spots, tyre marks and grit. Usually once or twice a year, often combined with a machine sweep; the car park sweeping guide explains the pairing.

Loading areas, service lanes and bin enclosures. Spills, leaked bins and food waste. Bin rooms and chutes are washed and deodorised wherever there is drainage.

Rendered and painted walls at low level. Washed at low pressure or treated and rinsed, never blasted.

Outdoor furniture, bollards and balustrades. Near the entrance, done with the entrance.

How often

These are starting points. A foreshore building in Redcliffe takes salt and sand that an inland office does not; a West End entrance under big trees grows mould faster than one in full sun. The walkthrough sets the frequency, and the inspection results adjust it.

Matching the pressure to the surface

The pressure that strips mould from hard concrete will also strip the face off a soft paver, open up old mortar joints and lift paint from render. A good contractor:

• checks every surface before quoting, which is why pressure washing should not be priced from a photo
• uses high pressure on hard concrete and low pressure on render, pavers and painted surfaces
• treats mould, gum and oil with the appropriate product first, so they lift at lower pressure and take longer to return
• treats stains individually rather than blasting them
• tells you which stains will lighten but not disappear, particularly old oil and rust in porous concrete

Delta's pressure washing is set up this way: treat first, wash second, with the nozzle matched to the surface.

Where the water goes

Run-off from pressure washing carries mould, detergent, oil and grit. It should be directed away from doors and away from stormwater drains, with barriers to steer it and vacuum recovery to collect it where it would otherwise enter a drain or the building. The Queensland Government publishes guidance for businesses on preventing pollution of stormwater at business.qld.gov.au, and a contractor should be able to explain how they manage water on your site before they start.

Work is done after hours so surfaces are dry before anyone walks on them and so the barriers and hoses are not across a busy path.

Safety

Pressure washing involves high-pressure water, wet surfaces, electrical equipment and sometimes work near traffic. Ask the contractor for the safe work method statement for the task and the safety data sheets for any treatment products. Delta carries $20 million public liability insurance, has WorkCover in place, and includes both documents in the compliance pack shown at the walkthrough.

What to ask before you book

1. Will you look at the surfaces before you quote?
2. What pressure and nozzle will you use on each surface, and what will you treat first?
3. How will you manage the run-off, and where will it go?
4. When will you do the work, and how long until the surfaces are dry?
5. Which stains do you expect to lighten but not remove?
6. Can I see the SWMS, the data sheets and the certificate of currency?
7. Can it be scheduled as a periodic line item in our cleaning scope?

Scheduling it

Like every periodic job, pressure washing happens reliably only when it has a date. For strata buildings it should be a separate line item the committee approves, as set out in the strata cleaning specification guide. In Delta's client portal the dates sit as scheduled tasks timed around the wet season, and the inspection score records the result.

What it costs, and what moves the price

Pressure washing is priced per job, and the price is driven by four things: the area, the surfaces and the pressure each one can take, the treatment needed for mould, gum and oil, and the water management the site requires. A plain concrete path in full sun is a quick job; a shaded paver entrance with old mould, soft mortar and a drain at the door takes treatment, low pressure and barriers, and costs more for the same area. Timing matters too, because after-hours work on a busy path is slower than a quiet weekend morning.

For regular clients the job is a periodic line item in the scope with its own frequency, so the committee or manager can see what each wash costs on its own rather than finding it inside a weekly figure. Delta prices every pressure wash after a walkthrough of the surfaces, in writing, before any work starts.

Next step

Walk the approach to your building on a wet week and look at the shaded sections. If they are green or black, the mould is already established. Book a free walkthrough and the owner calls you within 30 minutes during enquiry hours to look at the surfaces and give you a written price. Entrances in West End under the street trees and foreshore buildings in Redcliffe are examples of where this work earns its keep.

Questions people ask

How often should a building entrance be pressure washed in Brisbane?

Most entrances and paths need it quarterly or twice a year, with shaded areas done before and after the wet season. Car parks are usually once or twice a year. Exposure, shade and foot traffic decide it.

Can pressure washing damage pavers or rendered walls?

Yes, if the pressure is wrong for the surface. Soft pavers, old mortar, render and paint need low pressure or a treat-and-rinse approach. A surface check before quoting is what prevents damage.

Where does the water go?

Away from the building and away from stormwater drains where the run-off carries more than water. Barriers direct it and vacuum recovery collects it where needed.