A number of our readers also were having problems with their Trex deck, so we contacted Trex.
We spoke with Trex Customer Service Reprentative Ms. Pat McCarthy. We explained our problems and those that our web users are experiencing.
Pat explained that Trex decks have to be cleaned once or twice a year. She referred us to the Trex Cleaning and Care information on their website. . She mentioned that most ordinary deck cleaners would be fine and also mentioned some eco-friendly products like Corte-Clean and Chomp Pro.
Pat cautioned us about using full strength bleach or cleaners since they can lighten some of the darker colored deck colors like Madeira, Woodland Brown and Cayenne.
I told her that one customer had even power washed the deck and the stains appeared in two weeks. She said that power washing if not done properly could void the warranty. Trex suggests not more than 1,500 psi and that you keep the powerwash tip at least 12 inches or more away from the deck.
Pat then said that some mold may be due to improper installation of the deck. She mentioned that proper drianage between the decking was important.
You should try some of the products and see if they work. If they don't then call the Trex Claims Department at 1-866-923-1494. They are supposed to follow up on these matters.
Pat also said she welcomed calls from any Trex customers who were having problems. She can be reached at 1-800-BUY-TREX or at Question@trex.com