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  • Writer's pictureChris Martin

The Dos and Don'ts of Pressure Cleaning Your Deck

Wooden decks can add a lot of value to your home, not to mention look amazing, but as soon as they become dirty their value starts to diminish. Not only does a dark and dirty wooden deck look unattractive, but it can also actually be damaging for the wood and cause irreversible damage.




Any dirt, debris or moisture left to sit on your decking can be dangerous to the wood. Mould and mildew can infiltrate the planks and cause wood rot or cracks to form. Once this starts to happen it can mean that you’re left deciding whether to tiptoe around splintered wood or bite the bullet and replace the affected planks.


To head things off before they get to that extent, we recommended maintaining your deck by regular cleaning and maintenance. The fastest and most efficient way to clean your wooden deck is with a high-pressure cleaner, but pressure cleaning your deck can cause damage too.


High-pressure cleaners can be used to remove paint from walls and stains from concrete so you can imagine the intense pressure they can put out. Before you run out and rent a high-pressure cleaner there are some things you need to consider if you want to keep your beautiful wood deck looking fresh and avoid causing irreversible (and expensive) damage.

We’ve put together a list of dos and don’ts to DIY wooden deck pressure cleaning. It’s a must-read for anyone looking to use a high-pressure cleaner on a wooden deck.


Dos for High-Pressure Cleaning


Sweep Your Deck First

Leaving dirt and debris on your deck, then applying water at high-pressure can lead to scratching and even chipping. Use a soft broom to remove any surface dirt from your deck before you start pressure cleaning.


Wear Safety Gear

It’s important to protect yourself as well as your deck when pressure cleaning. Use gloves, safety glasses, long pants and closed-in shoes to prevent any spray from the high-pressure cleaner causing harm.


Know Which Wood You Have

Different wood can sustain different levels of pressure so it’s important that you know which type of wood you have. Softwood like pine or cedar can only withstand 500 psi to 600 psi, whereas hardwoods like Jarrah, Spotted Gum and Merbau can sustain pressures up to 1,200 psi. If you’re not sure which type of wood you have, speak with a professional pressure cleaner for a free quote.


Choose the Appropriate Pressure Setting

High-pressure cleaners are extremely powerful, and they aren’t all built equally, commercial high-pressure cleaners can reach up over 5,000 psi. Putting one of those on your deck would cause serious damage to the wood. If you’re renting a high-pressure cleaner or borrowing one from a friend, make sure it has a pressure control knob that will allow you to turn down the pressure depending on which type of wood you have.


Here’s our complete guide to pressure settings: High-Pressure Cleaning Your Property: How Much Pressure Do You Need?


Choose the Appropriate Pressure Spray Tip

High-pressure cleaners should come with the option to change the spray tip to control how wide your spray goes and the shape of the spray. When pressure cleaning a wooden deck, you need to use a fan tip that disperses the water evenly and gently, rather than a narrow tip that provides intense pressure on a small point. We recommend using a 40-60 degree nozzle.


Test Your Pressure

The advice we’ve provided above is general and we recommend testing the high-pressure cleaner on an inconspicuous area of your deck to ensure you’re not causing any damage before tackling the rest of the deck. Test the pressure on a small plank of wood in case you cause damage and need to replace it.


Test Your Range

Just like testing the pressure on the high-pressure cleaner, you also need to test the distance from the nozzle to the wood. Learn how close you can get to the wood without causing damage. Start from about 1 metre away from the wood and slowly lower the nozzle to 30cm off the wood.


Use a Sweeping Motion

When pressure cleaning your deck, it’s important to keep the nozzle moving to avoid applying pressure to one area for too long. We recommended sweeping the nozzle from left to right and back again in a straight horizontal line, not an arc.


Maintain Consistent Distance

When moving the nozzle, it’s important to keep it and an even distance away from the wood. This will keep your cleaning consistent and avoid applying damaging pressure. Keep your arms and legs bent when spraying the nozzle to allow you to maintain the nozzle height.


Don’ts for High-Pressure Cleaning


Too Much Pressure

The easiest mistake when pressure cleaning your deck is applying too much pressure to the wood and causing damage to the planks. It’s better to be reserved with your pressure levels and go over the area multiple times, rather than focusing on an area with intense pressure.


Too Close to the Wood

By placing the pressure cleaner’s nozzle too close the surface of the wood you can etch into the wood and create cracks, splinters and chips.


Swing Your Arms in an Arc

By moving the nozzle in an arc pattern you’re likely to vary the pressure you’re applying to the wood by bringing the nozzle closer in some areas. Try to keep the nozzle a consistent height away from the wood.


Start Away From the House

One mistake that people usually only make once is moving towards their house when cleaning. By doing this you’ll be bringing all the dirt and mould you’re removing towards the house with nowhere for it to escape. Start your cleaning at the house and push the dirt away into a drain or lawned area.


Go Against the Grain

One important tip to avoid splintering is to always move the pressure cleaner’s nozzle with the grain of the wood. This usually means lengthways along the plank.


If you’re not sure about any of the tips we’ve provided, contact DJL Services for a free quote to pressure clean your deck. We’re a Perth owned company with a great reputation for service and high-quality work.

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