Is pressure washing bad for my deck?

Pressure washing your deck

You may have read or heard your neighbor say that you shouldn’t pressure wash your deck, because you can damage the wood fibers, or even scar the wood. That is very true! In the wrong hands a pressure washer can cause considerable damage to the integrity of the wood.

The pressure washer is a tool that is powerful enough to etch brick, but in the right hands it can also be gentle enough to wash siding or very soft wood. To avoid damaging deck wood (etching, splintering, fuzzing), incorporate the following pressure washing procedures:

Pressure washer fan tips
  • Use fan tips of at least 30 degrees. White or green tips are best. Avoid red or yellow tips.
  • Use moderate pressure on your pressure washer, of no more than 800 psi.
  • Keep the tip at a consistent distance from the surface at no less than 8 inches, throughout the cleaning stroke.*
  • When changing directions with the wand, ensure the tip is greater than 12 inches* from the wood to avoid a “hard stop,” or visible line on the wood.

A correct stroke with the grain of the wood takes practice to achieve adequate proficiency to avoid damaging wood. That is why we recommend practicing first on your driveway or an old pallet.

The article is written by, and courtesy of deck professional, John Worth, owner of Deck Medic Lake Norman.

More information on deck care and maintenance

*Editorial Note: Experts differ on details regarding fan degree, psi limit on a pressure washer and the distance from pressure washer tip to the deck. These guidelines are conservative and not a guarantee that damage will or will not result from diviation to these guidelines.

Disclaimer: The information contained in this bulletin is provided in good faith and should be used for general information only. Viance, LLC makes no representations or warranties of any kind, express or implied about the completeness, accuracy, suitability and fitness for purpose of deck cleaning and staining products, or processes mentioned on this website. Viance, LLC expressly disclaims, and does not undertake or assume any duty, obligation, or responsibility for any decisions, reactions, responses, actions, failure to act, by you or any other person or party as a result of or in reliance on, in whole or in part, the information contained in this content, or for any consequences or outcomes arising from or caused by any such decisions, reactions, responses, actions, or failures to act.