Everything has an expiration date, including a deck sealer. Deck sealer can be oil, acrylic, latex, silicone, or wax-based. Because it's essential to regularly maintain a deck that has been sealed, you must have a supply of deck sealer on hand. It works out to be more economically viable if deck sealer is purchased in bulk, as opposed to purchasing in smaller tins. If you have a lot of deck treatment left after the first use, don't worry, it won't expire any time soon.
Oil-based sealer, or paint, has a shelf life of around five years. Store in a cool, dry place.
Acrylic- or Latex-based Sealer
Acrylic- and latex-based sealer are both water-based. Similar to paint in its consistency and shelf life, if stored in a cool, dry place, it should last approximately five years.
The silicon-based sealer has a very long life when used, is a semi-permanent option, and is hard to remove once applied. Its shelf life is around five years.
Wax-based sealer is the least expensive option in the short term. It is difficult to remove, with a short protection life span. The shelf life for waxed-based sealer is around five years.
Always mix deck sealer well before applying to wood.