Lee Roy Jordan Lumber

Will the Power Washer Harm or Cut into My Decking?

power washerIt can be difficult to maintain your decking when it comes to cleaning practices. Dirt can stain the wood over time due to the weathering, as well as constant foot traffic pressing into the wood grains.

Using a power washer can solve this issue. but it has to be set up properly and used carefully. Misuse can expand the wood from water pressure or spraying at the wrong angle.

The short answer to the question? -Yes, the power washer can harm or cut into your decking! But that is only if the process is done improperly.

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Let’s take a look at some important pointers for completing this task successfully with no harm to your beautiful wood deck.

The Equipment

First thing to do is setup your pressure washer. This includes choosing the nozzle for the optimal amount of pressure.

The maximum pressure we recommend is 100-150 bar, this can do a good job of cleaning without causing damage.

However, for the sake of damage control, we recommend you begin at the lowest pressure setting. This “test run” allows you to gauge the strength of the spray without causing harm.

Turn it up gradually until the pressure level appears to be effectively pushing dirt and debris from the deck surface. Why we don’t recommend going above 100-150 bar, you may find a lower pressure level perfectly effective.

There is normally a selection of accessories that come with a regular pressure washer.

A great accessory for your deck is a fan tip nozzle. This attachment can clean at a good angle, and is easy to control.

If you are willing to spend some more money, the best attachment we recommend for this job is a patio cleaner. True to its name, this accessory was literally designed for deck cleaning.

The patio cleaner attachment covers a larger area and provides a very even cleaning to your deck surface. Additionally, it works quickly and is also splash-free.

Detergent or No?

Next we want to consider whether a detergent is necessary. This decision will depend on the condition of the deck. For instance, after a long damp winter, grime can build up and be very difficult to remove.

However, be sure you use a detergent that is specifically designed for use on wood decks. Using a safe product on a gunked-up deck can definitely cut down on the overall cleaning time and make the job easier to complete.

If you elect to use a detergent, be sure you follow the instructions on the packaging. We don’t cover that in this article, as instructions for usage may vary from one product to the next.

Now that you have all of your supplies, it’s time to discuss technique.

Damage-Free Power Washing

All woods have a certain grain pattern. It is important to use your sprayer along the deck graining rather than against it. Spraying “crosswise” can damage the decking surface and make it vulnerable to rot and splintering.

You want to keep the nozzle at the same height whilst you clean. A good height is approximately 2 feet above the surface.

[Easy to follow DIY video for deck washing]

If the grime is still not moving, you can move closer by 2 inches at a time, until the buildup washes away. However, you don’t want to bring the nozzle closer than 6 inches, in order to avoid pressure-related damage to the wood.

Keep the nozzle moving in smooth passes back and forth, in a controlled motion. Washing as steadily and evenly as possible is the best method for good cleaning practise.

If you hold the nozzle in the same spot for too long a period of time, this can damage the decking. Again, the whole idea here is to use enough water pressure to clean the deck without harming the wood.


Power washing your deck is a lot like many other tasks in life: done recklessly or improperly, it certainly can cause damage. But if you use the right tools, the right amount of water pressure, and the right technique, there is no need for concern.

More tips on deck restoration: How Do I Return my Deck to its Original Color?

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