Wood stain does go bad, but it will last in the can for between three and six years, provided you use proper storage techniques. Storing wood stain in open containers or in extremely low or high temperatures will cause your wood stain to become unusable much more quickly. Water- and latex-based wood stains typically last for just two to four years, while oil-based wood stains can last for three to six years.

The plastic in composite decking boards protects them enough that you do not need to paint them to prevent warping. In fact, painting composite decking voids the warranty of some manufacturers. Painting can also increase maintenance on the deck, as you must paint regularly to keep it looking its best.

Staining pressure-treated wood is a recommended practice. While inherently resilient, it's not impervious to moisture and UV exposure. Staining treated wood is feasible and recommended for enhanced protection and longevity. Applying stain and sealant safeguards against degradation, prolonging its life span. These measures shield the wood from environmental threats while augmenting its aesthetic appeal, ensuring your investment endures the test of time.

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.