We have been using Corte Clean on our deck for a few years now and don’t consider using anything else. We have a Trex deck that was built about eight years ago and in areas that don’t get enough air flow underneath, we get spots of dark mold. The Corte Clean makes such an amazing difference! We clean it in the springtime and along with spraying and waiting the suggested time, we also keep a stiff bristle broom and give the section a little scrub and rinse. It’s an easy process and once it’s done, the deck feels so clean and feels good on bare feet. We really enjoy our deck after it’s cleaned.