Can You Clean Composite Decking With Bleach?

M. John
deck cleaner

When choosing a cleaning solution for your ultra decking, you should select a good type for the decking. Knowing the right type of cleaner to use for your decking will also prevent any chance of damage. Bleach is a common cleaner used in cleaning. Can you clean composite decking with bleach?

Why Do Decking Owners Use Bleach For Deckings? 

It is believed that bleach can kill mould and remove mould stains quickly; that’s why most decking owners buy bleach. Mould can grow on composite decking if you don’t clean your decking regularly. Besides that, when the deck is exposed to moisture, it can accelerate mould growth on the decking.

Some homeowners use bleach on the deckings to get rid of the mould or grease. But does bleach kill mould? Bleach cannot kill mould on porous surfaces like composite decking. Although it can kill bacteria and other organisms on non-porous surfaces, it doesn’t work for mould on porous surfaces.

Chlorine bleach is the most common bleach sold in stores. It is also known as Sodium Hypochlorite. It is a cleaning agent used in cleaning to remove stains fast. If there is a stain on your composite decking, you may be tempted to use bleach. Bleach removes stains quickly by making the surface area white or colourless. But is it safe to clean composite decking with bleach?

Is It Safe to Clean Composite Decking With Bleach

ash colour bleached composite deck

Bleached composite deck

If you apply bleach to remove stains on composite decking, the bleach can remove the stains quickly in minutes. Most of the time, decking owners with mould stains use bleach to remove the stains on their deckings. Of course, bleach can give you a quick fix when removing stains, but it comes with a price. If you apply chlorine bleach to composite decking, the bleach will damage your decking. How?

Chlorine bleach removes stains by making the area white or colourless. If you apply bleach on composite decking, the bleach will damage the decking colour. It will fade the composite decking colour, thereby damaging its looks. Apart from fading the decking colour, bleach can also cause serious damage to the entire decking.

We all know that composite decking can not crack or splinter, unlike wood decking. But if you apply bleach to your composite decking, the bleach will react with the decking. It will make your composite decking chirp, crack, or splinter.

In addition, bleach is also corrosive to metals. When applied regularly on a deck, bleach can damage the fasteners that hold the decking in place. When this happens,  the decking will collapse. It will lead to the entire breakdown of your decking.

Can You Clean Composite Decking With Bleach?

Considering the effect bleach can have on composite decking, the response to the above question is No. It is not recommended to clean composite decking with bleach. Chlorine bleach contains sodium hypochlorite, which can ruin your entire decking.

Apart from damaging your decking, bleach is also a toxic chemical. If you accidentally come in contact with bleach, it can irritate your skin. Exposure to chlorine bleach can also cause serious headaches, respiratory problems, vomiting, etc.

Applying bleach to remove any stains on the composite decking can cause irreparable damage to the decking. Bleach can cause your composite decking to splinter. It can also damage the entire decking. The cost to replace an entire decking can be very expensive. However, you should avoid using bleach to clean your composite decking.

If you want to clean dirt off your composite decking, you can use soapy water. For oil or grease stains, use hot water and soap. You can also apply baking soda and vinegar to remove oil stains. For mould stains, pour a mould remover on the mould and use a bristle brush to scrub the affected area.


You should not clean composite decking with bleach. Regular use of bleach to clean composite decking can damage the entire decking. It can cause your composite board to chirp, splinter, or crack. In addition, bleach can also corrode the decking fasteners, thereby collapsing the deck.

Also, learn how to finish composite deck end.


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