Exterior wood decking when left neglected oxidizes from the Ultra Violet rays from the sun. This will patina the exposed layer of wood cells turning the deck gray. Cleaning the deck first with a deck cleaner and power washing will remove this layer of graying wood cells while removing accumulated dirt, grime, mold, mildew, and algae.
Prepping your wood deck is the singular most important step when it comes to getting maximum performance out of your deck stain. Failure to prep and your stain will fail faster than it should and will not give the wood it’s natural beauty.