It’s important to make sure the wood on a new deck is properly seasoned. Seasoning a deck is simple: Once you build it (or have a pro do so), just leave it alone so it can acclimate to the environment. If you don’t give the deck proper seasoning time before staining, the stain can lock in any lingering moisture and cause mold, rot, and other moisture issues down the road. Give the wood at least four to eight weeks to season before you stain.

Applying too much sealer to a deck might seem like extra protection, but it can cause more harm than good. Wood is a porous material with a limited capacity to absorb liquids. When you go overboard with sealer, the excess can't soak in and instead forms a film on the surface. This leftover layer is prone to peeling, cracking, and trapping moisture, ultimately defeating the purpose of sealing in the first place. 

A wood deck requires annual cleaning and regular inspections for loose or broken boards, nails, and screws. It should be refinished by applying a stain or sealer every two to three years to protect the wood from water damage, rot, mildew, and sun fading. The exact frequency can depend on the climate and the deck's exposure to sun and moisture. If your deck is painted, it will need repainting approximately every 10 years. Signs that your deck needs refinishing include faded, splintering, or warping boards.

The best way to clean your decking is to clear debris from the gaps between the boards, sweep the surface, rinse it, apply cleaner, rinse again, and let it dry fully. A homemade deck cleaner made of two gallons of warm water and 1/2 cup vinegar is a simple cleaning solution for both wood and composite decking. You can sprinkle baking soda on any spots with mold or mildew, then scrub the area and rinse clean.