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How to pressure wash a deck

How to pressure wash a deck
(Image credit: Getty Images)

Knowing how to pressure wash a deck is an essential skill to keep your outside space clean and tidy. Using a pressure washer is an effective way to get rid of even the most stubborn dirt, muck and grime - but how do you use one? Here is your guide to how to pressure wash a deck. 

What the expert says…

Fiona Jenkins says, “As long as you know what you're doing and you're careful with the pressure, a power wash won't damage your decking. However, it's important to test it in an inconspicuous area before getting to work to ensure the pressure levels are correct for your type of deck.”

Before starting to clean your deck, you may have wondered if using a pressure washer carries the risk of damaging it. Landscaping expert Fiona Jenkins says that careful testing and selection of pressure is the key to not causing any damage. 

“If you have a timber deck, the pressure washer may cause splintering or damage to the fibres,” she says. “If the deck already has some splintering, you can further damage it with a pressure washer. If you have a composite deck, your pressure washer may scar the deck boards if the pressure is too high. It may even chip the boards if the pressure becomes too intense. 

If you’re considering buying a new pressure washer, make sure to consult our guide to the best pressure washers (opens in new tab) you can buy in 2022. With models from Karcher, Stanley and Simpson, you’ll find the perfect pressure washer for you. Our experts have spent over 65 hours meticulously researching and testing the devices in the roundup to make sure they’ll be perfect for you and your needs. 

How to pressure wash a deck

We consulted with Fiona Jenkins to find out the most important steps to take when pressure washing a deck. 

Fiona Jenkins
Fiona Jenkins

Fiona Jenkins is a landscaper with over 25 years of experience in the industry. As a gardening expert for MyJobQuote (opens in new tab), one of the UK's top trade-matching sites, Fiona offers her expert advice to tradespeople and homeowners and has also been featured as a gardening expert for a range of reputable publications. 

Step 1

Jenkins says that choosing the right setting, testing the pressure and maintaining a consistent distance from the wood is key to pressure washing safely. “First, choose the right setting and spray tip,” Jenkins says. 

“Use the lowest possible setting that works. The pressure for soft woods such as pine or cedar should be around 500 – 600 psi. Harder woods may tolerate slightly higher pressures. However, you should never go over 1200 psi for a deck. Use a 40 – 50 degree fan spread. You can also use a rotating tip if you use it carefully. 

Step 2

“Test the pressure in an inconspicuous area. Start with a 500 – 600 psi pressure and then increase it until you find the right setting that allows you to clean the deck properly. 

Step 3

“Now you can power wash the deck. Hold the wand a couple of feet away from the surface of the deck and engage the trigger. Lower the wand closer to the deck as needed. Try to avoid going any closer than six inches as this may damage the wood. Clean with a sweeping motion and try to maintain a consistent distance. 

Feather the spray lengthwise, parallel with the deck boards, to work with the grain. Overlap each area slightly to maintain an even clean.”

Why is it important to keep a deck clean?

Apart from just looking good, there are multiple reasons why it’s important to keep on top of the cleanliness of your deck.

Jenkins says that as well as helping it stay looking as good as new, and increasing the lifespan of the desk, pressure washing your deck regularly can even improve the value of your home.

“There are several reasons why you should keep your deck clean,” Jenkins explains. “Firstly, it maintains your property value – if your deck is poorly maintained, this can decrease the value of your home. A well-maintained deck can help to increase the value of your home as it improves the curb appeal.

“It will also improve the appearance of your home. If you keep on top of cleaning your deck, this will ensure that it remains looking as good as new for as long as possible. Furthermore, health and safety wise, if you don’t keep on top of maintaining your deck, this can make it vulnerable to the elements and can lead to things like algae, mould and mildew. These can pose a risk to your health and safety. 

“Cleaning your deck will also increase its lifespan. Keeping on top of maintaining your deck can help to increase the lifespan and ensure that you can continue using your deck for many years.” 

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Deborah Cicurel is a London-based freelance journalist specializing in lifestyle, travel, interiors and more.  She also regularly reviews lifestyle, tech and parenting products, putting them to the test to ensure other consumers are well-informed before making important purchasing decisions.

With contributions from