How to Apply Deck Sealer

Whether you are building a new deck or doing maintenance on an old one, applying sealer will extend the life of the deck as well as add to its beauty.


Apply Deck Sealer
Sealer will stop water from seeping into the wood, preventing mildew and fading. While applying sealer should be a part of regular deck maintenance, it isn’t difficult or time consuming and can easily be done by the homeowner. .

Do the “water test” to determine whether your deck needs to be sealed. Sprinkle a small amount of water on the deck. If the water soaks in, your deck needs to be sealed, but if the water beads, it doesn’t need to be sealed. Do the water test every spring.

Remove plants and furniture from the deck.

Cover nearby shrubs and plants with a drop cloth to avoid contact.

Use sandpaper and a wire brush to remove stubborn dirt.

Use a deck cleaner and brightener on older decks. Your deck may have faded or discolored from the sun and weather, and the sealer will cling better to a clean deck.

Let the deck dry thoroughly for several days.


Make sure the area you are working in is well ventilated and that you will have several dry days between 50 and 90 degrees.

Stir the sealer. Don’t shake the can or bubbles may form that will show up when you apply the sealer.

Pour the sealer into a roller pan.

Use a roller to apply the sealer in large areas starting at the back edge. Don’t saturate the roller; it’s better to apply two light coats rather than one heavy one.

Use a brush or a rag to apply the sealer in small areas.

Apply an optional second coat.

Remove the tarp from shrubs and plants.

Let the sealer dry 24 hours before using the deck.

Things You Will Need

  • Rags
  • Paint brush
  • Roller
  • Deck sealer
  • Wire brush
  • Sand paper
  • You may need deck cleaner


  • Don’t let the sealer puddle. It will become gummy and difficult to remove.
  • To minimize puddles and gummy surfaces, have a second person with a broom or paint brush follow you to smooth out over applications.


  • Deck sealer is flammable. Carefully rinse out brushes and rollers. Lay rags out flat to dry and dispose of carefully.

About the Author

Catherine Rayburn-Trobaugh has been a writer and college writing professor since 1992. She has written for international companies, published numerous feature articles in the "Wilmington News-Journal," and won writing contests for her poetry and fiction. Rayburn-Trobaugh earned a Master of Arts in English from Wright State University.