The Difference Between Deck Stain and Deck Sealer

You will hear these two words used interchangeably by most people. An outdoor deck stain is actually a tinted deck sealer. Sealers will waterproof the deck and prevent moisture from causing damage to the wood. A clear sealer will protect the deck against moisture infiltration but will not prevent the deck from turning gray in the sun. Deck sealers were developed to provide UV protection and moisture protection in one step. Many people are under the misconception that you have to apply a deck stain and then follow with a type of sealer similar to what you would use on interior wood. This would be a bad practice. Interior clear coating sealers like urethanes and varnishes do not have the same vapor transmission characteristics as a product designed for exterior wood. This means that moisture will get trapped underneath a clear coat. That moisture will continuously fight to evaporate until eventually it finds a way out through a tiny fissure. This fissure will then expand and in a short time, your decks would be covered with bubbles and a peeling coating. This is very difficult to remove and could require an expensive intervention by a deck restoration company. The most popular deck stains out there made by Cabot’s, Wolman and Behr are actually all tinted deck sealers.