How to properly power wash your deck

Power wash your deck

power wash image of deck

Why power wash your deck?                                                                                                        We all enjoy spending  time outdoors. Often much of that time is spent on our decks. Whether grilling, entertaining or just watching the kids play in the back yard the deck is our out door “living room”. Unlike the other living areas of our homes however, the deck is exposed to every extreme of weather nature can throw at it. If you want to protect your investment in your deck and keep it looking good year after year there are some simple steps you should take.

Cleaning your pressure treated deck

Usually it is a lack of maintenance that causes problems on homes but ironically one of the main reasons for deck deterioration is too much maintenance. With the best of intentions many home owners subject their decks to brutal assaults with a pressure washer ever year.  Understanding what your deck is made of and how it was treated will help prevent damage when you power wash your deck.

The wood in older decks was treated with Chromated Copper Arsenate and newer decks are treated with varieties of Alkaline Copper Quat as well as Sodium Borate and Zinc Borate preservatives. Regardless of the treatment method it all has the same purpose. That purpose is to create an environment in and on the wood in which the micro-organisms responsible for wood decay can’t survive. It also makes the wood unpalatable to termites and most other wood consuming insects. Without these preservatives your deck would decay and be devoured by insects just like a log in the forest.  You can however,  power wash your deck without diminishing it’s longevity using the methods detailed herein.

Pressure washers are almost always used at too high pressure for treated decks and while they wash away the dirt and stains they also blast away the preservatives that are the life blood of a deck. I have seen time and again deck boards that were soft and crumbly on the surface and weak throughout because of improper pressure washing.

The trick to power wash a deck lies in using the proper cleaning agents . . . and patience. First wet down the entire deck with plain water from a hose or pressure washer with a low pressure fan nozzle. If there are plants around your deck wet them down also. Then using a pump up sprayer or siphon attachment apply diluted liquid laundry detergent to the entire deck. I use about 1 or 2 cups detergent per gallon of water. If there is mildew add about a cup of bleach along with the detergent.(always exercise caution and observe all safety warnings when using cleaning products or power equipment) Let this work for about 10 or 15 minuets. Rinse any over-spray off nearby plants while you are waiting. On areas with heavy stains or mildew apply extra cleaning solution and scrub with a soft bristle brush. Rinse with a hose or pressure washer with a low pressure fan tip and never let the tip get closer than 12” to the deck. Repeat the above process for stubborn stains. Be sure to rinse nearby plants thoroughly.

This method will allow you to power wash and clean your deck without washing away the preservatives that protect it.  See evolution of treated decks for more insights on deck longevity and check out staining decks and sealing decks for tips on keeping you deck looking good longer.

Check back for more maintenance tips and visit our website Gallery page to see photos of our work.

Remember Wood’s Home Maintenance Service provides a complete line of maintenance, repair, and building services

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About Tony Wood

Tony is a life time resident of North Carolina with over 30 years experience in multiple facets of the industrial, commercial and residential construction industry. For the past 23 years he has owned and operated Wood’s Home Maintenance Service, providing services primarily in Johnston, Wake and Sampson Counties of North Carolina. ______________ ______________________________________________________ The information contained in this Blog is opinion derived, from hands on experience of over 30 years in the construction industry and by extensive research by the author. All postulations are referenced to the geographic location in which this experience was gained.

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One Response to How to properly power wash your deck

  1. Great post with good information. If you need a good pressure washer check out

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