I have a vinyl TimberTech deck in PA which I installed around 2009. It has another brand of composite railing, which is no longer in business. It had a maple tree above it which dripped sap all over it, which I have since cut down and miss the shade! In addition, it got green algae and mold, in addition to other stains, all over it. Pressure washing alone didn't do a thorough job, as stains were still viable. I then used Corte Clean years ago, which did the best job of any product I have tried. I've since tried the products at Home Depot and Lowe's, which don't work nearly as well. I just purchased more Corte Clean.