The best deck paint for old decks is a paint that will create a seal and protect the wood from the elements. Look for a coatings product that is specifically designed to be used on decks. When painting an old deck, it's important to sand down any peeling or chipping paint before applying the new coat. Be sure to clean the surface of the deck well before applying any paint, and follow the instructions on the can closely to ensure proper application.

If you're looking for a paint that will last, look for a product labeled as an "exterior semigloss." When choosing a color, keep in mind that light colors will show dirt and stains more easily than dark colors. You may also want to consider using a sealant or primer before applying the paint.