We live in the state of Washington & it was the time of year to clean our ZomeTek composite decks that we had built due to a remodel of our home. The decking had green mold stains, grease stains from BBQ & dirt due to use & weather. In following the instructions that are online on how to properly use Corte-Clean we were so delighted with the outcome. Our deck looked like the day it was installed. Core-Clean is a fantastic cleaner for composite decking. What we also appreciate is knowing that using Core-Clean that we will get a long lasting deck that looks good. We are satisfied a customer that Highly recommends this product for cleaning composite decking!