Prior to staining a newly built deck or re-coating an older deck, clean the deck surface with a common deck cleaner. Use a deck brush to gently scrub the surface and then pressure-rinse clean (500-750psi) or hose down completely with a fresh water rinse (for previously stained decks, a higher water pressure may be necessary). Allow to completely dry before coating.
The type of wood deck that delivers the best performance for wood stain and is easiest to maintain is one built from pressure-treated wood. If possible, always use the highest grade of pressure-treated lumber for your deck and use galvanized screws for fasteners.
Next to pressure-treated decks, deck stains perform best over red cedar and redwood. White cedar will generally require more frequent applications of wood stain. Exotic hardwoods are generally denser and require more frequent applications of wood stain.
Because decks are fully exposed to the elements and are subject to a lot of weather and abuse (i.e. rain, ice, snow, shoveling, salt, foot traffic, etc.) expect to apply maintenance coats on the flat exposed surfaces every 2 to 3 years. The stain on the vertical railings normally should last between 4 to 5 years. Individual circumstances will dictate the frequency of maintenance requirements.
HELPFUL HINT: An effective way to extend the life of a deck finish on the flat surfaces of your decks, rails, and steps is to remove standing water as soon as possible. The easiest, quickest, and least abrasive method for removing water is with a squeegee. Any deck stain will deteriorate faster if water is allowed to stand and puddle before evaporating on its own