How to clean a patio or decking with a pressure washer

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When you add a patio or decking around your garden it makes for a beautiful area for dining and entertainment but it’s important that you keep this area clean to prevent the buildup of things like algae and dirt. Using a pressure washer is a fast and effective way to do this regularly.

A pressure washer will help you remove even the most difficult of stains and algae that are trying to take over your patio. It will help you avoid any manual scrubbing or scraping by using powerful pumps to spray a forceful blast of water that removes dirt and grime from your decking or paving slabs quickly, much more effectively than a regular garden hose.

What you need

In order to effectively clean with a pressure washer, you will, of course, need the pressure washer, in some cases different detergents, a hose, hose adapters, and safety gear such as a safety goggles.

Check out some of the best pressure washers for cleaning patios in this review we recently did

You can rent or buy pressure washers. If you are planning to clean your new deck or patio regularly, buying a pressure washer can make for a very sound investment, one that can be used all over your garden including spaces like paths and driveways.

How to Use a Pressure Washer to Clean Your Patio:

Step 1 – Clear the area

Start by removing any garden furniture you have, BBQ’s, any pots and planters, or ornaments.

Take a brush to sweep away any loose debris or even consider using a leaf blower to get rid of the loose dirt or leaves. 

Step 2 – Getting setup

Make sure that water is running freely to your hose before you start. You want to run the water through your pressure washer after you connect the hose just to remove any air bubbles. The hose needs to be, in most cases, a minimum of 7.5 meters in length, most domestic pressure washers like the ones purchased from DIY stores and online such as the Karcher K4 will work with most standard hoses. Some pressure washers you can rent require high pressure and a larger 3-inch hose so its best to check as they are not always suitable for use at home.  If you have a hose reel for your hose, make sure it is fully unwound and there are no kinks or knots in it so that you can maintain constant water pressure as you are cleaning.

With most pressure washers you will need universal connectors as well as a tap adapter to connect your hose. If you are renting your pressure washer you can make sure all of these components come with it at the time of the rental. If you purchase your pressure washer, you might have to purchase the adapters separately but make sure you have them either way before you begin. The connects can be purchased for a few pounds at DIY stores and online.

Step 3 – Powering the pressure washer

Once the hose is connected to the pressure washer you want to connect your pressure washer to your mains electricity supply unless you have a petrol pressure washer. After this is done, turn it on to begin pressurizing the system or if you have a petrol model start the engine.

Consider applying a detergent

Kärcher K7 Premium Full Control Plus Home Pressure Washer Review
Kärcher K7 Premium Full Control Plus Home Pressure Washer

At this point, depending on how dirty your patio or decking is you might want to apply a detergent to the surface according to the instructions so that the detergent has time to dissolve the dirt that is otherwise sticking to the surface which will make it much easier to clean. There are certain detergents with properties designed to reduce the buildup of dirt in the future after it has been applied so this can protect your surfaces and make it easier to clean going forward. Other detergents come with protective elements against weather damage and some are specially designed for materials like stone or wood. You can even find some for your vehicle if you want to use your pressure washer on your car in the future. Some models like the Karcher K5 now some with the option to insert bottles of detergent for stone and decking into the pressure washer itself.

Step 4: 

pressure washer pencil jet for removing stubborn stains

Some organisms can be very difficult to remove with a standard patio cleaner but most pressure washers have what is called a rotary pencil Jet and that gives you increased power. Using that jet specifically will help you to get rid of even the most stubborn of dirt but the increased power associated with these specific nozzles mean they should only be applied on hard surfaces like stone and paving. If you try to use such a powerful nozzle on soft surfaces like wood it can damage the paintwork or finish.


  • If you use your pressure washer on your driveway, try to use a very low setting. High settings on a block paved driveway are so powerful they actually remove the sand that holds those blocks together. So, if you plan to use a pressure washer regularly on a block paved driveway you will need to replace the sand regularly.

How to Use a Pressure Washer to Clean Your Decking:

Cleaning decking with a pressure washer

When cleaning decking with a pressure washer it can be more susceptible to damage so care needs to be taken. Follow the same steps as cleaning a patio but also take the following into account.

There are specific detergents you can buy for woodwork that is designed to protect your decking against any subsequent UV damage while also dissolving dirt.

Avoid any rotary pencil jet nozzles as these will damage the decking.

Some extra tips to bare in mind

  • If you have an extension cable make sure it is no longer than 10 meters in length and provides a constant rating of 13 amps. Also, make sure it is fully unrolled if coiled as it can get very hot.
  • Make sure you use a special detergent specifically for the type of decking you have when removing difficult grime.
  • Always wear safety goggles when using a pressure washer especially if using detergent.
  • Be careful if you are using the pressure washer near plants as they can quickly fall over or break, even if they are in otherwise secure pots.

Overall, pressure washing is a very fast and simple way to clean your decking and your patios. There are pressure washers that are perfectly well suited to cleaning driveways, garden furniture, even your vehicles which makes them a great investment for all of your outdoor cleaning needs.

The versatility of pressure washers means that you can find something suitable for the size garden you have as well as a variety of accessories and washing detergent for the type of material you have on your patio or your decking. With just a little bit of work now and again you can keep your backyard looking as good as new without any manual scrubbing.

Have you considered cleaning your patio or decking without a pressure washer – See our recommended patio cleaner than you apply and leave – no pressure washer needed

Also, see – the best decking cleaners

Learn how to apply decking oil after cleaning your decking

Welcome to my site, my name is John and I have been lucky enough to work in horticultural nurseries for over 15 years in the UK. As the founder and editor as well as researcher, I have a City & Guilds Horticultural Qualifications which I proudly display on our About us page. I now work full time on this website where I review the very best gardening products and tools and write reliable gardening guides. Behind this site is an actual real person who has worked and has experience with the types of products we review as well as years of knowledge on the topics we cover from actual experience. You can reach out to me at

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