How to Clean a Driveway: Pressure Cleaning Concrete and Pavers Safely

To clean a driveway safely, sweep first, match the pressure to the surface, hold the nozzle at a steady distance and work downhill so the dirty water runs away from areas you've already cleaned. Concrete can usually handle a firm clean, but pavers, older concrete and softer stone need a gentler approach, and the jet can wash the sand out of paver joints if you aim straight at them.

At Aussie Duo Cleaning Service, we pressure clean driveways, paths and walls for homes and businesses across Canberra and Queanbeyan through our high pressure cleaning service. This guide explains how to clean hard outdoor surfaces safely, what to do about moss, oil and wash water, and when it makes sense to book a professional.

Moss, algae and leaf litter make outdoor surfaces slippery, especially on shaded paths and south-facing areas that stay damp through Canberra's winter. The Queensland Government's tips to reduce falls at home point out that outdoor tiles and paths can become slippery when wet, and recommend keeping paths free of moss and leaves. NSW Health's home safety checklist gives the same advice and adds that paths shouldn't be uneven or broken.

A thorough clean before the Christmas break also makes a noticeable difference if you're hosting family, selling your home or preparing a rental property for inspection, because driveways, entrances and outdoor entertaining areas are the first things visitors notice.

Not every outdoor surface should be cleaned using the same method. Kärcher's guide to cleaning pavers warns that a water jet can quickly damage concrete and terracotta surfaces, while natural stone such as granite or basalt is usually sturdier. It also advises working gently on pavers with very wide joints, because the stones can loosen.

As a general guide:

• Plain concrete driveways usually handle a firmer clean, but older or cracked concrete needs more care.
• Concrete and clay pavers need a lower pressure and a wider spray, so the surface and joints aren't damaged.
• Natural stone, sealed or coloured surfaces may need a gentler method, so check with the supplier or installer first.
• Painted walls, render and timber are better suited to a low-pressure clean than a strong jet.

Before you start, relocate vehicles, pot plants and outdoor furniture, and make sure you understand where the water will run, then work through these steps:

Paver joints are the component most frequently damaged during pressure cleaning. Kärcher notes that aiming the jet directly at the gaps will wash out the joint material, so you may need to refill the joints with sand afterwards. Sweeping the joints first, and keeping the nozzle moving across the surface rather than into the gaps, helps keep the sand in place.

Moss, algae and weeds tend to return in damp, shaded areas, so removing loose dirt and leaf litter regularly helps slow regrowth, and clearing weeds from the joints by hand beforehand makes the clean faster and more consistent.

Oil stains on concrete are considerably more difficult. A degreaser applied before cleaning breaks down fresh oil, but old or deep stains often fade rather than disappear completely, because the oil has soaked into the surface. It's worth setting realistic expectations before you spend hours concentrating on a single patch.

In the ACT, water that runs off driveways and paths ends up in the stormwater system. The ACT Government's Healthy Waterways program explains that there is no treatment plant for the stormwater system, so whatever enters a drain flows on to local creeks and lakes. Penrith City Council's stormwater fact sheet gives similar advice in NSW: don't wash or blow material down the stormwater drain, and don't dispose of chemicals, oils or washing liquids in it.

Before you start, sweep up leaves, soil and debris and put them in the green bin, rather than hosing them into the gutter. If you use a cleaning product, choose one suited to the surface, use only what you need, and plan how to stop the runoff reaching the drain.

A pressure washer is considerably more powerful than it appears. WorkSafe Victoria's safety alert on high-pressure water jetting warns that a water jet can pierce the skin and inject contaminated material into the body, and that flying debris can cause eye injuries. Its guidance is aimed at workplaces using industrial equipment, but the same basic precautions apply at home.

Wear safety glasses, enclosed shoes and long pants, never direct the nozzle towards people, animals or your own feet, and keep children at a safe distance while you work. Avoid using a pressure washer from a ladder, and switch the machine off and release the pressure before changing nozzles.

A small path or patio is usually a manageable weekend project, but a professional clean is often the more practical choice when:

• the area is large, such as a long driveway, a full backyard or a strata car park
• the surface is pavers, natural stone, coloured concrete or an older surface that could be damaged
• there's heavy mould, algae or oil staining that needs pre-treatment
• you need the work done before a sale, an inspection or an event, without hiring equipment

We match the pressure to the surface, pre-treat mould and oil where needed, and assess each site before starting so we can plan how to manage the wash water. Our driveway cleaning service page explains what's included. Our high pressure cleaning costs $4.40 per square metre including GST ($4 + GST), with a minimum job of $187 including GST ($170 + GST). For example, a 60 m² area comes to $264 including GST ($240 + GST), and we confirm the price before we start.

Aussie Duo is a family-owned Canberra business that has been cleaning since 2013, and we pressure clean driveways, paths, patios and walls across Canberra and in Queanbeyan. We just need access to the area and an outdoor tap, so you don't need to be home. For commercial sites, read our guide to car park cleaning, and if you're moving out, see our end of lease cleaning service.

Request a free quote or call 02 5501 3316. We usually reply within 30 minutes during business hours, Monday to Saturday, 7am to 7pm.