Can You Power Wash Composite Decking?

We know you aren’t a numpty, and you likely already know that the only way to get a thorough clean is to start with a blank canvas. So, when deciding to power wash composite decking, it’s important that you remove all furniture, lifting carefully to prevent scratching and scraping. Once the deck’s free from furniture, be sure to sweep any debris such as leaf litter, dirt, build up, dust, and grit with a soft bristled brush. Done? Great. You’re good to get started.

From here, you can begin cleaning off any stubborn decking stains, algae, and dirt with a jet power washer. However, do not use a pressure washer with greater than 3100 psi pressure, and do not hold it any closer than 25cm above the composite decking boards. If you decide to do so, you’ll risk damaging your boards. The sheer force of the water pressure can cause the surface of the decking boards to splinter, causing long-term harm that can’t be easily fixed.

Even with a lower pressure power washer, the direct force of a direct stream of pressure can cause damage to your composite decking. To mitigate the risk of this, use a fan attachment. These can be bought separately and work to spread the flow of the jet over a wider area, reducing the amount of focused pressure being directed toward your boards.

Whether you are cleaning woodgrain or grooved boards, the simplest approach is to clean following the grain of the board. Work in a left to right motion, following the length of the boards, cleaning one at a time; this will aid drainage. Dirt residue, leaf mulch, and superficial moss and algae will be more well established in grooved decking boards, so really take your time with them. Trust us, your deck will thank you.

After removing any excess debris and dirt, apply Owatrol cleaning solution – or even a basic household detergent – for a squeaky-clean finish. Owatrol Compo-Clean is water-based, kind to the environment, and safe to use. Just dilute it, apply it, and wait for the results to appear. Chances are you’ll only have five minutes to kill before you see the benefits.