How to Pressure Wash a Deck (A Step-By-Step Guide)

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how to pressure wash a deck

Your backyard deck is exposed to a lot of weather elements and dirt over the course of its life. 

As it ages, you might notice your deck getting dull and dingy from the dirt that it accumulates. When this happens, it could be time to break out the pressure washer. 

Pressure washers are a valuable tool for anyone who wants to keep their outdoor features clean. It can save a lot of scrubbing and elbow grease and usually gives a sparkling end result. 

We have put together an in-depth guide on how to pressure wash a deck. Using this guide, you can safely and effectively get your back deck looking like new again. 

By following these steps, you can also be sure that your pressure wash job will be done correctly. 

Pressure Washing a Deck: Basic Idea

It may seem like pressure washing a deck is a simple enough job. However, there are some steps you need to be sure to take if you want it to be professional quality. These steps are:

  • Scrub and prepare the surface
  • Wash with the power washer
  • Apply a renewer or brightener
  • Sand the entire deck 

Why Pressure Wash Your Deck?

why pressure wash your deck

When a piece of furniture or a structure sits outside for a long time, it accumulates dirt. This may seem obvious enough, but it gets dirty in a different way than something like a floor or counter. 

Because a deck is exposed to the elements, it is susceptible to a wider variety of debris. 

Dirt from the rain, tracked dirt, vegetation, and dust all land on the deck and sit for long periods. On top of this, you walk on your deck and this embeds the dirt into the pores and grain of the wood. 

As a result, this dirt is much harder to remove and will require extra help to get down into the wood. A pressure washer can get below the surface and expel that embedded dirt, grease and grime. 

On top of the effectiveness, it is also much easier to use a pressure washer than to clean manually. Your shoulders will thank you for the break. 

Clean the Surface

Before you begin, you are going to want to sweep and lightly scrub the deck with a broom and mop

While this might seem counterproductive, it is actually very important. 

Loose dirt can be pushed into the pores of the wood with the pressure washer. Because of this, you will want to remove it and make sure the deck is free from loose dirt and dust.

You should also take this time to clear the deck of any furniture or barbecues. Get as much of the deck surface exposed as you can so you can thoroughly hit it with the power washer. 

Pressure Wash

pressure wash

Once you have cleared and cleaned the deck surface, you are ready to start washing. Set the power washer between 500 and 600 PSI at first to be sure it won’t be too powerful. 

Before you start blasting away at the deck, do a couple of test strokes. Keep the nozzle a few feet away from the deck and slowly inch it closer. 

It is best to try and keep the nozzle at least 6 inches away to avoid damaging the wood. 

Start close to the house and work your way outwards. Use long, smooth strokes and keep with the grain of each deck plank. 

With each stroke, come back in the other direction and overlap. This will help you to get a smooth, even clean without missing any spots. 

Apply a Brightener

After you have cleaned the entire deck, you can then apply a chemical brightener to finish it. 

Find a brightener that contains sodium hydroxide. This will help remove any mildew or mold that has found its way into the pores of the wood. 

Apply the brightener with a brush or roller and then rinse it away with the pressure washer. 

This will give the wood that “like new” color and vibrancy that you are looking for. 

Sand the Deck

The combination of pressure washing and brightening solution will cause the wood to have a rough texture. Because of this, you will then want to sand down the deck and smooth it out

Sand the entire surface and be sure to remove any rough pieces that have broken off. These are a guaranteed splinter waiting to happen. 

Sanding will also help remove any remaining mold or mildew that the brightener and washer missed. 

Sand until you are satisfied that every splinter and rough spot is removed. Then, you can give the deck a final rinse with the pressure washer. 


faq how to pressure wash deck

  • Is it better to paint or stain a deck?

In general, it is better to stain a deck than it is to paint it. 

Paint will only sit on the surface of the wood, leaving it vulnerable to cracking and damage. Stain gets down into the pores and seeps into the wood itself for a longer-lasting finish. 

  • Can you power wash a pressure treated deck?

You can power wash a pressure treated deck. However, you should make sure that you do not use the higher power settings and always start low. 

Pressure treated wood tends to be softer. This makes it more likely to be damaged by heavy-duty power washing. 

  • How often should you pressure wash a deck?

To ensure that your deck stays clean and mildew-free, pressure wash it once a year. 

This routine will keep problems like deterioration and damage due to mold from occurring. On top of that, your deck will stay looking new for much longer. 


By following the above steps, you can easily pressure wash your deck and keep it nice for years. Keeping up on regular cleaning is a great way to not only make it look nice, but protect it. 

Regular upkeep is the best defense against damage from mold and other deterioration. Plus, it’s an easy and satisfying job to do.

Photo of author


Michael J. O’Connor is a writer and marketing specialist from the Bay Area of California. A graduate of Sonoma State’s Creative Writing program, he spent many years as a contractor and carpet layer, learning the ins and outs of flooring and general contracting. When he’s not typing away at his desk, he enjoys hiking with his dogs, woodworking and collecting rare books. See full biography here.

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