Power Washing Your Deck – the good, the bad and the ugly

With all the warm weather we’ve been having on the East Coast, more and more people are opening their doors and stepping outside. Spring is less than a week away and it’s now time to prepare your outdoor living spaces for the coming months, including, you guessed it, cleaning.

For those who have wood decks, renting a power washer to clean your deck can make a huge difference, but when done incorrectly, it can also result in unwanted damage. We’ve seen some homeowners who had to replace decking boards after trying to power wash their space because they weren’t 100% sure on how to use the machine.

The key word is “power.” It’s called power washing for a reason. That thing is strong! Power washers (or similar machines) are used to clean grimy streets and etch bricks so it’s not surprising that it can do a number on your deck if done incorrectly. Before using the machine on your deck, take it to an area where you can test it and become familiar with the pressure. A driveway, sidewalk or street will work.


The pressure. On most residential projects, you will rarely need a machine that is more than 1500 pounds per square inch. Even that setting may be too much and cause some damage to both wood and composite decking. The only way to tell if the setting is too high is to watch as you clean. If you see more than dirt coming off your deck, turn the setting down.

The nozzle. The nozzle of the pressure washer can be adjusted to different angles so it can be used for multiple purposes. For the standard deck, a 40 to 60 degree fan nozzle setting is best as it spreads out the power over a greater area as opposed to a zero degree setting that would blast your deck too strongly and will damage boards.

Also, it is important to be careful and not stand too closely to the area you are cleaning. You should be able to stand comfortably while spraying the area 3-4 feet in front of you. If you are too close to the surface being power washed, you can cause unnecessary damage to both your deck and yourself. The water can bounce back at you if you are too close.

Here is a great guide from the Family Handyman on how to use a pressure washer efficiently, effectively and safely.

If you have any questions on care or replacement of decks, please contact your local Archadeck office.

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