Jul 8 2009

How to Clean a Deck (Don’t Use Chlorine Bleach)

no-bleachWhen it comes to cleaning your deck, some people might feel tempted to pull out some bleach from the garage and get started. Stop! Before you do this, you need to make sure that you are very careful. Chlorine bleach does an excellent job of killing bacteria and viruses, but has not been proven effective in killing molds on porous surfaces.  It also destroys the lignin in your wood deck, disrupting the way it is bonded together. The wood will become more prone to aging to an unattractive gray color and splintering along the surface. When it comes to chlorine bleach, think of it as a sanitizer, not a deck cleaner. It should stay in areas of the house such as the kitchen, on the counter, or in the bathroom cleaning surfaces there.

Chlorine bleach can cause  deck stains or sealers applied to the wood to fail. It will remove any natural color as well leaving you with a bland, unattractive color. Bleach itself is 99% water. Water is one of the main contributors of the growth of harmful bacteria and mold. The ionic structure of bleach prevents chlorine from penetrating into porous materials such as wood—it just stays on the outside surface, whereas mold has enzyme roots growing inside the porous construction materials—however, the water content penetrates and actually FEEDS the mold. This is why a few days later you can notice darker, more concentrated mold growing (faster) on the bleached area.

If you want to know how to clean a wood deck the right way, you should be using oxygen bleach. In all of your detergents in your laundry room you can find oxygen bleach. It cleans the fabrics without disrupting the color or damaging the fabrics. Usually it can be combined with water, applied, let sit, and rinsed off no problem at all. Oxygen bleach give you a clean deck and will not harm vegetation surrounding your deck, which is a huge plus and will save you time from covering your grass and landscaping to protect it.

Another plus to this type of wood cleaner is that most of the time, a power washer is not necessary in order for it to work. A simple garden hose is sufficient. The chemicals are powerful enough by themselves to do the work if allowed to sit for 10 to 15 minutes.

Oxygen bleach will actually help to preserve the life of your deck by not damaging the fibers and keeping the lignin that holds the wood together healthy and strong. Healthy, clean wood makes for an attractive deck. Remember that not just any bleach will do a good job at cleaning your deck and maintaining its health. Beware of any bleach with the chemical name sodium hypochlorite, this is chlorine bleach and will indeed damage your deck.


10 Comments on this post


  1. Hilda said:

    Oxygen bleach is fantastic! It cleaned the vinyl siding to my house with almost no elbow grease, safely disinfected all my kids’ Little Tyke plastic furniture, and my husband grabbed some out of the laundry room to test a patch of the deck with it- worked great!

    August 6th, 2009 at 1:36 pm
  2. Deck Staining Tips said:

    Thank you, another good article about no bleach. Not only does it breakdown the wood fibers, it also changes the pH of the wood thus causing a premature coating failure.

    February 18th, 2011 at 11:02 am
  3. Kate said:

    My husband didn’t know that you aren’t supposed to use chlorine bleach to clean our deck… He had our neighbor put the bleach into the pressure washer and it left lines all over the deck. So the neighbor thought he’d just pour the bleach from the jug straight into the deck and use a mop to rub it in. Now I can see the poor wood is definitely in bad shape. He didn’t do this to the entire deck, just 1/3 of it. It sucks that our deck is only a year old. How
    Do we correct it?? My husband is out there now spraying it with sealer. So we have one part that is white (and splotchy from the bleach) and the other parts he hadn’t gotten to yet. How do we save it and make the deck color look even all over???

    May 2nd, 2011 at 9:36 pm
  4. administrator said:


    If he already sealed the wood then you have a even bigger mess to fix.

    You would need to strip off everything and start over.

    Sorry you have such a mess!

    May 2nd, 2011 at 11:27 pm
  5. Larry said:

    What if sealer has not been applied yet? Is there a way to fix the white that the bleach caused? My sister did this in a solution (bleach, Dawn and water) that I use for washing the house down.

    May 18th, 2011 at 7:23 pm
  6. administrator said:

    It would help to use a the Defy Wood Cleaner and Wood Brightener to help restore the natural color.

    May 18th, 2011 at 10:37 pm
  7. Leslie said:

    So once I use the oxygen bleach as a cleaner, and the deck dries, I can stain? Do I need a brightener first?

    August 28th, 2011 at 10:27 pm
  8. administrator said:

    You should always use a wood brightener to neutralize a cleaner.

    August 29th, 2011 at 10:12 am
  9. Charrles B. said:

    I have a log home and most log home manufactures suggest bleach to clean weathered logs. I have used diluted bleach succesfully for a long time. It is necessary to power wash it off and maybe use a neutralizer before any finish is applied. Most log suppliers and experts suggest 25% bleach and 75% water. This is for bare logs. My logs were then coated with an oil base translucent UV protective coating. It is important to not leave it on to long. Most deck cleaners i have looked at seem to contain the chemical name for chlorine bleach and certainly smell like chlorine bleach. You do not want to use chlorine bleach on Cedar however. Oxygen bleach works much better.

    February 11th, 2013 at 12:26 pm
  10. administrator said:

    Charles, bleach is bad for wood as it breaks down the lignin that holds the wood cells together. This has been proven numerous times. Best to use a Oxygenated Wood Deck Cleaner. In addition, you should follow the advice of the stain manufacturer, not the log home manufacturer as prepping is specific to the stain being used, not the wood.

    February 11th, 2013 at 12:36 pm


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