My composite deck is three years old. Last year there were a lot of spots so I hired a professional to power wash the deck. The spots came back within two months. I searched to a composite deck cleaner on the internet and found Corte Clean. I watched the demo and decided to give it a try. It’s been a couple months since I cleaned my deck with Corte Clean and the deck looks brand new. This product really works. I did not have a sprayer so I just used a brush to spread the cleaner. That worked out just fine.