How can I remove mold from a composite deck?Composite decking materials are made from a combination of wood fibers and plastic. Several manufacturers have been involved in class-action lawsuits, largely because consumers claim the wood lookalike harbors mold.
Trex, a popular manufacturer of composite decking, says mold will not damage the deck boards. Still, the manufacturer recommends cleaning the deck periodically, and offers these guidelines for removing mold from its composite decking:
If you see mold on your deck, clean it with a commercial deck wash containing a detergent and bleach (the ingredient on the package might call it “sodium hypochlorite). The bleach, Trex says, will remove the mold, but also could lighten the color of the boards.
Trex recommends these products for cleaning mold from composite decking:
- Olympic Deck Wash
- Expert Chemical Composite Deck Cleaner & Enhancer
Repeat the process until you can no longer see any mold. Because mold is not always visible, clean the deck with this product periodically to kill any spores that you can’t see.
As an alternative to chlorine bleach, Trex recommends a product called UltraMean. You will have to scrub the product into the deck immediately after applying it.
To prevent mold:
Composite decking is not a food source for mold. Still, the dirt and debris that collect on a deck does feed the spores. So keep your deck clean. A few tips:
- If you have flower pots on your deck, set them in saucers large enough to catch overflowing soil and water so that never touches the deck boards.
- Direct the water from your gutters and downspouts away from your deck. Moisture can cause mold to breed.
- Clean in between the boards, where dirt and moisture can cling.
- When you install a composite deck, don’t place the boards too close together. Gaps that are too small won’t let dirt and water out once it seeps in.