Our TimberTech deck is thirteen years old. Its color is beige and we chose to have the "grain" side up installation. We cleaned with Corte Clean in July only because where we live (Omaha, Nebraska) the weather is very unpredictable and, many times, the weather does not meet the requirements to use the product. Plus, it was just time to clean the surface of dirt and mold. Our deck is mostly in shade with our house and a tree blocking the assisting sun. The temperature at application was between 75 and 90 degrees, it took six hours to clean. Corte Clean worked wonderfully for us. I think at the higher temperatures we had, the necessity of sun is lessened. We used a maintenance level of cleaner (2.5 cups of cleaner) and, even though it had been two years since the last cleaning, it worked its magic. Using Corte Clean is rather labor intensive but well worth the effort. Thank you Corte Clean.