How to Clean Composite Decking

Composite decking is made up of recycled high-density polyethylene plastic and reclaimed wood fibres. The durable polymer outer shell encapsulates the boards to form an impermeable layer that protects from scratching, staining and fading. Despite composite decking offering a long lasting, low maintenance alternative to timber; you will still need to clean your decking.


Never Use Household Bleach

A common practice when dealing with a mouldy wooden deck is to use Chlorine bleach to clean it. It’s often the go to household product for any dirt, grime and mould removal. This is not a great idea when it comes to composite decking. Besides how bad it is for the environment, it can cause your colour to fade after many applications.


Always Use Sodium Percarbonate Based Cleaners

What is Sodium percarbonate? Sodium percarbonate is also known as Sodium Carbonate Peroxyhydrate, is a pure high-quality oxygen bleach. Oxygen bleach breaks down to oxygen, water and sodium carbonate upon decomposition. It dissolves into water rapidly to release oxygen and provides powerful cleaning, bleaching, stain removal and deodorizing capabilities in addition to being effective at killing bacteria, fungus, viruses and algae. It has the added advantage of having no odour. Some of the other benefits include:

  • No environmental hazards – breaks down to oxygen, water and sodium carbonate (soda ash) in your wash water.
  • Effectively kills a wide range of bacteria, mildew, algae, viruses, fungi.
  • Colour safe and fabric safe. It brightens colours and prevents fabrics from becoming yellowed or darkened.
  • Effective stain removal on a multitude of surfaces.


Instructions for Using Sodium Percarbonate

  1. Dissolve 50-60g of oxygen bleach per litre into warm/hot water.
  2. Clear the decking of any loose debris, leaves, rubbish first with a brush.
  3. Apply the solution to the surface and allow it to work for around 30-60 minutes.
  4. Scrub with soft-bristled brush.
  5. Rinse off with clean fresh water. Each litre of the solution will clean approximately five metres square of the surface. For stubborn stains, further applications will be necessary.


Extra Tips for Using Sodium Percarbonate

Only work on a small area at a time. The product is likely to foam when scrubbing with the brush. Do not be alarmed if the foam turns grey/black. That is the dirt, not any colour coming away from your decking boards. Make sure you let the Oxygen bleach stay on the decking for at least 10 minutes (ideally 30, as above), and make sure the surface remains wet. That means re-covering if necessary during the time period. A white powder residue may be apparent when your composite decking is dry. This is just the soda particles, which can be swept away.


Composite Decking


Step Away From the Pressure Washer

Pressure washing is a fine art at the best of times, only the hardy of us will use it to clean our cars from example, and we urge you to be cautious when considering using it on your composite decking. Composite decking material is softer than natural wood and therefore can be “etched” more easily. Once the material has been “opened up”, this can lead to a host of other issues including chipping, sun damage, staining of the plastics inside the opening.


Stay Proactive!

Clean your Ecoscape deck at least twice a year, preferably in the spring and in the autumn. Remember, proactively cleaning your composite decking is the key to spending less time and money in the long run.

Ewa studied Law at the University of Gdansk, Poland before moving to sunny England and joining the Ecoscape team in the summer of 2016 as a sales assistant. If you even call in and she isn’t at her desk – call the search party! Lives and breathes Ecoscape and loves the occasional ‘Fat Friday’ treat.