Tips For How To Clean Composite Decking

How To Clean Composite Decking

Bottom line, older TREX, TimberTech, and other wood content composites should be bleached and brightened. Please contact the manufacturer or read the literature that came with your decking if you have any doubts on power washing. A power washer can create serious damage to a composite deck if the pressure is too high, an inappropriate nozzle is used, and/or the nozzle is held too close to the surface. Always start in an inconspicuous area when power washing to test that it is not damaging the decking. The safest course will always be to hand wash your composite decking.

Decking & Railing Duos

Will the Defy deck cleaner likely get the black stains out of the composite deck pores that still remain? If the stains can be removed and I then apply the clear Defy sealer, what likely will be my deck color?

• Once the material has been opened up, many issues can arise including chipping, sun damage, and mold staining the plastics inside the opening.
• Pressure washing too close or using too much pressure can ruin your deck.
• Composite decking material is softer than natural wood, meaning it can be “etched” more easily.
• Once mold has stained has occurred, it can be extremely hard to remove.

The Composite Deck Cleaning Process

Painted wood decks, often coordinated to match the trim on a home, come with special cleaning issues. Harsh cleaners can damage the painted surface, weakening it and leading to cracking and peeling. A gentle all-purpose deck cleaner that does not contain ammonia is usually the best choice for a painted wood deck. The label should specify the cleaner is safe for painted surfaces.

Buyers Guide: The Best Deck Cleaners

The best part of composites is that, with the exception of food stains, you only have to clean your deck for aesthetic reasons. For wood decks, not cleaning often enough can lead to more costly maintenance. Thurston said the green and brown stains you describe are probably mold and mildew, which come in a variety of colors besides basic black.

Design & Price

I make no guarantees on Trex because even they now it will not be 100%. Fred, that’s odd, composite decks shouldn’t have this issue. Maybe try using our Composite Deck Cleaner and see if that takes it off. If you have a pressure washer, maybe give it a light rinsing after allowing the cleaner to set for minutes. To clean a composite deck, sweep it with a broom or leaf blower at least once a week to get rid of dirt and debris. If your deck is still dirty, hose it down, scrub with a brush and soap, then, rinse with a hose. For a faster cleaning option, try using a pressure washer.

Many of the composite companies use wood content in them as well. is referring to was the original TREX which was Red Oak which is a hard wood that leaves a dark black tannin. Anyone who has had to clean off oak leaf stains from concrete can attest to that.

To remove mold from older Trex products, the company recommends using a deck wash that includes detergent and sodium hypochlorite, commonly known as bleach. It specifically recommends Olympic Premium Deck Cleaner ($9.98 per gallon at Home Depot) and Expert Chemical’s Composite Deck Cleaner & Enhancer ($19.98 a gallon at expertchemicalinc.com). The cleaning process will go best if you select the right cleaner to begin with. I hate bleach because it kills plants and vegetation and it’s terrible to work with. It will kill the mildew spores, but doesn’t necessarily remove them from the surface of the wood.