How to Remove Mold From a Trex Composite Deck

Trex composite deck material is an alternative to wood. Decks made of wood need to be sealed annually to keep from absorbing moisture, which rots the timber. Composite decking does not need sealing, but does require proper cleaning and maintenance to keep the material from staining. Remove mold and mildew as soon as possible to keep it from permanently staining the Trex composite deck.

Remove Mold From a Trex Composite Deck
  1. Remove furniture and plants from the Trex composite deck.

  2. Wipe loose mold from the deck with old rags. Place the rags in a plastic trash bag. Put the trash bag into an outside trash receptacle.

  3. Sweep the deck free of debris and dirt with a broom.

  4. Mix 3/4 cup of bleach into a gallon bucket of water. Dip a sponge into the bleach solution and apply to the mold on the deck. Saturate the mold with the bleach. Allow the bleach to remain on the mold for five minutes, giving it time to kill the fungus.

  5. Scrub the mold with a scrub brush. Rinse the mold and the bleach from the deck with the garden hose or buckets of water. Ensure the bleach is completely rinsed from the deck. Allow the deck to dry before replacing the furniture.


  • Never mix bleach with ammonia as it can give off toxic fumes.
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