When to Clean a Deck You should have your deck thoroughly cleaned at least once per year, but you’ll definitely want to have it power washed before you put a new coat of stain or sealant over this (which you should do every few years). Power washing before staining or sealing will help to ensure proper absorption and even coverage. Overall, the best way to clean your deck thoroughly is to hire a professional for power washing. However, there are some other steps you can take to improve the look of your deck. Feel free to contact us today to find out more about our deck cleaning and restoration products that are easy to use.