What is the greenest way to clean wooden decks? Is a diluted solution of bleach the best method?

Asked by Maria Michalczyk
Belgrade, MO

I used to clean my wooden garden furniture with a 10% solution of bleach water, and it seemed to do a good job removing the mildew buildup. Is this a green method of cleaning yard furniture and can the same solution be used to clean wooden decks?


Doug Cameron, LEED GA

Answered by Doug Cameron, LEED GA

Austin, TX

EcoSafe Spaces, LLC

August 17, 2011

Rather than using a chlorine bleach. I recommend using a non-chlorine washing powder made of sodium percarbonate and sodium carbonate.

  • "Oxygen powder" or "washing powder" is very similar to baking soda, and can be purchased in the laundry aisle of your local grocery store for around $1 per pound.
  • A 100 square foot deck would require less than 2 pounds of washing powder.

How I do it

I like to first wet the entire deck with a 9 to 1 water to washing powder solution.

  • Immediately after, while the deck is still wet, I lightly apply washing powder by itself (using a salt shaker method), attempting to cover the entire deck with a very thin layer.
  • Don't worry if you don't get total coverage.
  • Let the this solution sit for at least 30 minutes, preferably during the day.
  • Follow up with a thorough scrubbing. I like to use a hose/scrubber attachment.

With a little elbow grease, your old deck should look as good as new.

Preserve the cleaned wood

After the wood has had a chance to dry, you can apply natural wood stabilizers and/or stains to further the level of protection from the elements. 


For more information:

Read "Can I use boiled linseed oil on wood during the rainy season?" a Q&A answered by Florian Speier.

Tagged In: decking, cleaning

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