Composite decks, often called Trex decking, require some basic care and maintenance to keep them looking good. Although composite decks require less work than standard wood decks, certain things can still leave stains or marks, such as scuff marks from shoes. Cleaning scuff marks from Trex decking is fairly simple. You should do it as soon as you notice the marks to prevent the marks from setting into the deck material and making the stains more difficult to remove.
Mix together warm water and ½ cup dishwashing liquid together in a gallon-sized bucket.
Dip a soft bristle cleaning brush, available at many hardware or home repair stores, into the cleaning mixture and apply it to the marks.
Scrub in a back-and-forth motion, reapplying the soapy mixture as necessary until the scuff marks are gone.
Use a hose to rinse the area with clean water.
Mix together a solution of ¾ cup bleach and 1 gallon of water if the above steps do not remove the stains. Dip a clean brush into the solution and scrub the marks until gone. Use this solution too if mold is evident on the decking.
Rinse well with clean water.