How to Remove Mould From Composite Decking

M. John
How to
Wet composite deck

Mould can stain the decking, thereby making it look less attractive.  Apart from that, it can also make the decking slippery. Mould can grow on both wood and composite decking. To retain the appearance and functionality of your ultra decking, you need to get rid of mould from your decking. We will concentrate on how to get rid of mould on composite boards. But we will first consider why you need to get rid of mould. After that, we will consider how to remove mould from composite decking.

Why You Need to Remove Mould on Composite Decking

Like wood decking, composite decking is also susceptible to mould. It contains both recycled plastic material and wood fibers that make it vulnerable to mould. However, composite decking differs from wood that can get damaged by mold. Mould can penetrate wood decking and decompose it.

Composite decking, on the other hand, can not decompose. Mould can only get into the crevices of composite decking and stick to the wood particles. Mould on the composite deck surface can also make the decking slippery and cause you to fall or trip.

Mould thrives well in a dark, shaded, and damp environment. It is a fungus that can decompose organic material like wood.

They can grow on any surface, including wood and composite decking. The mould clings to the surface of the decking and can make the decking look aesthetically displeasing. Mould can stain composite decking, thereby making it look less beautiful.

Aside from that, mould can also affect your health. It releases airborne spores that can cause allergic reactions in some people. Additionally, mould can cause headaches, rashes and can also affect the respiratory system. Since homeowners build decks close to the house, mould spores can easily drift into the house. Hence a reason you have to remove mould on your composite decking.

 Removing Mould on Composite Decking

Considering the effect mould can have on your health and your decking, there is an urgent need to remove the mould on your composite decking. While mould can infiltrate and make a wood decking unusable, it can’t damage composite decking.

Removing moulds on composite decking is easy. If you want to remove mould from composite decking, use a mould remover that is not harsh on composite decking material. These cleaners may not be harsh on wood decking but might ruin your composite decking. Some of these mould cleaners can bleach the colour of composite decking, you should avoid such kind of mould remover. The ideal way you can get rid of mould from composite decking is by scrubbing the decking with vinegar and baking soda.

Step One- Gather the Materials Needed

First, gather all the material you will need. You will need water, vinegar, baking soda, and a soft bristle brush. Additionally, you will also need a bucket, a hose, or a pressure washer(no greater than 1,300 psi)

Step Two – Pre-rinse the Composite Decking 

Pre-rinse the composite decking with a garden hose or a power washer. Use a power wash no greater than 1,300 PSI to remove the mould that sticks on the deck surface. Ensure you use the pressure washer to remove as much mould as possible on the decking surface.

Step Three: Prepare the Vinegar Solution

You can prepare the vinegar solution by mixing the vinegar with water. Additionally, homeowners can use apple cider or white vinegar, whichever is available. Mix about two parts of the vinegar with one part of the water in a bucket. After you have prepared the vinegar solution, pour it directly on the mould.

Step Four – Sprinkle Baking Soda

After you have poured the vinegar solution on the mould, sprinkle some baking soda on it.  Let the baking soda sit and soak for 20- 30 minutes before scrubbing. Scrub the area well with the bristle brush to remove any leftover mould.

Step Five – Rinse Thoroughly

Lastly, rinse the composite decking with water to remove any trace of the mould remover. Now your composite decking will look sparkling clean with no trace of mould on it.


You can remove mould from composite decking with a mild mould remover like vinegar and baking soda. Pour the mould remover on the decking and scrub the composite decking to remove all traces of mould.


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