How to Sand And Refinish a Deck Floor

When building a deck, the builder treats the wood with a sealant that protects the deck from the outdoor elements. This protection typically lasts for one to three years, after which point the deck has to be resealed. While the sealant does protect the wood, the effects of weather and sunlight tend to dull the wood stain, bleaching the wood to the point that the deck appears old and weathered. Erase the effects of weathering by sanding the deck to remove the existing finish, and then refinishing the deck to add vibrant new color to the existing wood. You can complete the process in a single weekend to make your old deck appear nearly new again.

Sand and refinish your deck to restore it to a like-new appearance.
  1. Clean the surface of the deck by removing any loose dirt and debris with a broom, and then scrubbing the wood with a pressure washer and deck cleaner to remove any ingrained dirt or mold and mildew. Wait about two hours for the wood to dry completely.

  2. Place 20-grit coarse sandpaper on a drum sander. Put on ear protection, a dust mask and safety goggles. Sand the surface of the deck to remove the old finish, following the grain of the wood and using a back and forth motion across the deck planks. Use a floor edger to sand the edges of the deck against the house. Sand until all traces of the old finish are gone and you're left with only bare wood. Use the broom to remove any dust from the sanding process.

  3. Remove the 20-grit sandpaper and mount 60-grit paper to the sander. Sand the surface of the deck with the new paper to smooth out any rough areas on the deck wood, including any gouges.

  4. Switch the sandpaper a third time to 80-grit and make a final pass with the sander over the deck, creating a surface devoid of any noticeable scratches.

  5. Place a 120-grit screen onto a buffer and go over the deck's surface a final time before applying the stain. The buffer pass smooths the surface of the deck completely removing any flaws in the wood as well as opening the pores in the wood for the stain.

  6. Apply the wood stain to the surface of the deck with a paint roller. Roll along the wood grain, working from one end of the deck to the other. Roll on the stain in layers until you've created a coat of stain that has the color depth you desire. The more layers you add, the deeper the color will be. Allow the stain to dry for 24 hours.

  7. Roll on a layer of deck sealant to protect the wood from the elements. Work with the wood grain when applying the sealant, making sure to cover the entire surface of the deck. Allow the sealant to dry for 24 to 48 hours before using the deck.


  • Wear protective gloves and safety goggles throughout the refinishing project.