How to clean your decking with a pressure washer

Sweep the Decking

Before you start firing on all cylinders, it’s important to give the decking a quick once over with a broom to make sure you’re not going to send debris flying around at high velocity once you start pressure washing.

You can actually scratch and damage paint on the deck or even chip the wood if there are larger rocks and other debris that the high-pressure cleaner will push around.

Wear Safety Gear

Just because you’re hooking the pressure up to the garden tap doesn’t mean that you’re dealing with your average garden hose. The water from an electric pressure washer can reach over 2,000 PSI and if you’re using a commercial hot pressure washer you could be dealing with 5,000 PSI of high temperature water that will cause serious damage to your skin on impact.

At the least you should be wearing closed-toe shoes and long pants that fully cover your legs, however, for your safety and protection, we’d also recommend gear like thick gloves and a pair of goggles to protect your eyes from any loose debris that’s kicked up during cleaning.

Don’t Use Too Much Pressure

While it’s always tempting to crank the PSI to the max when using a pressure washer, wood is a soft surface that can be damage if too much pressure is applied to it. Different woods can handle different amounts of pressure as well, with a harder oak being able to withstand pressures of up to 1,500 PSI, while pines and gums require pressure to be kept in the 400-600 range.

Make sure you’re using the correct nozzle as well, as the 0° nozzle’s spray pattern will be too high intensity and will cause damage. Start with the lowest pressure 40° nozzle and then determine if higher pressure is needed — we would recommend going no higher than a 25° nozzle.

Test Before You Spray

Instead of blasting swathes of your decking with high-pressure water right out of the gate, test a small patch of the decking that’s out of sight first to make sure your settings are correct.

Spray Evenly Across the Decking

Rather than power cleaning patches of decking continuously, use a sweeping motion to give the wood an even clean. Applying high-pressure water to one area continually can start to wear the wood, so this will help to avoid damage as well.

Don’t Get Too Close

As with all pressure washing jobs, maintain a reasonable distance from the surface you are cleaning. Holding your pressure washer nozzle too close to the wood could damage your deck and cause you more problems than you started with.

Use a Broom Attachment

If the main thing you’re looking to clean is your deck, one of the best attachments you can pick up for your pressure cleaner is a broom attachment. The extra scrubbing power is a must if you have caked on mud or moss that you need to contend with as it means you can loosen tougher patches of dirt without need to use extreme pressure.

If you have a Karcher pressure washer, you can get the PS 30 Power Scrubber Surface Cleaner that has high-pressure nozzles that help to circulate the water through the brush for a complete clean of your decking that you can’t really match with a standard scrubbing brush.

This particular brush attachment is great because it offers a top tier clean and is compatible with all of the major Karcher pressure washers from the K2 Pressure Washer all the way to the newer K7 range.

Don’t Clean Against the Grain

Try to avoid cleaning against the grain of the wood as you can cause damage doing so. Clean in sweeping motions along the grain to get a nice even clean.

Use a Specialised Deck Cleaner

While general cleaning products like soaps and detergents will be fairly effective at washing your deck, specialised formulas will have added bonuses like UV treatments to reduce wood darkening and added dirt removers that will help to strip grime from your deck more easily.

Try a Foam Cannon or Soap Nozzle

A foam nozzle or foam cannon can give you extra suds that’ll cling to dried dirt more easily and help to break down engrained soil or plant matter. Some pressure washers, like the Bigboi WashR Flo 2600Psi Pressure Washer, come with a foam cannon attachment as part of the package, which can mitigate some of the cost of buying one separately.

Start Cleaning Close to Your Home

There’s no point starting your cleaning job away from your house and slowly pushing all the dirt and mould towards the back door. Start next to your house and work your way down the deck, pushing the grime and debris towards a drain or lawn so the kids can’t track all the mud you removed straight through the living room.

Get Your Decking Ready for Summer

Thanks to a high-pressure washer, cleaning your decking doesn’t have to be a massive undertaking with a trickling hose and a series of brushes and rags. With a bit of care and attention, a pressure washer can help you make short work of the moss and debris that’s been building up in the winter and create a BBQ-ready decking come summertime.

Another great way to clean your deck is with a soft washing treatment, which can get you fantastic results without the need for extreme pressures that can damage your wood planks or paintwork.

If you’re after any attachments, hoses, or deck cleaning solutions, head to your nearest Repco store or browse online for our full range of products.