How to Clean, Seal or Stain a Deck

A water test is the easiest way to ensure that the wood can absorb sealer or finish. Sprinkle water on the deck. If it soaks in immediately, you can seal the deck. If the water beads up or stands on the deck, you may need to wait to seal it. 

Before cleaning, sealing or staining, inspect the deck for safety. Deck Safety and Maintenance will help you prepare your deck from start to finish.

When learning how to re-stain a deck or how to repaint the deck, always read the manufacturer's directions for your deck stain and sealer. Drying times differ based on air temperature and humidity. Before you start, check the deck boards for needed repairs to splits or popped-up nails. Here are some additional tips to make the job go more smoothly.

• Don't apply deck products in direct sun. The finish will dry too quickly and won't absorb into the wood.
• Use the water test to check your deck every few months to ensure the sealer is still repelling water.
• Regularly sweep off debris.
• If you have a brand-new deck made of treated lumber (as opposed to cedar or redwood), wait at least a few weeks before sealing it for the first time. This allows the wood to dry so the stain is absorbed.
• Decide if you're staining a deck with oil-based stain or a water-based stain. Oil-based stain takes longer to dry, but it's more durable and the color can penetrate deeper into the wood. Water-based stains aren't as messy and dry quicker.
  
• If you've replaced a warped or damaged board, the new wood won't be the same shade as the rest of your deck. If you want to stain immediately, use an opaque or semi-transparent stain to create a blended surface.
• An alternative to stains or sealers is a resurfacer or restoration product. These finishes are like a very thick paint that's applied with a brush or roller. They're great for covering deck boards and don't show woodgrain.

Before you tackle deck maintenance, staining, sealing or restoration, consider the following: 

• It’s tricky to work backward. For example, if your deck is currently covered in an opaque stain, it’ll take a great deal of stripping and surface preparation to ready it for a clear or wood-toned stain. It’s easiest to continue with solid/opaque coverage. 
• The more opaque a stain, the quicker it’ll show wear and weathering. A solid stain might need reapplication every year, while a clear or wood-toned treatment will likely last longer. 
• Darker colors, particularly solid/opaque and semi-transparent stains, will absorb heat more easily. They could make walking barefoot on the deck uncomfortable. 
• For a decorative look, select two or more colors that work together for decking, rails, post caps, stencil work, etc. 
• For high-traffic areas, choose a good decking stain or sealer that's specially formulated to repel water, resist mildew and prevent fading.
• When choosing a stain, remember that the finished color varies based on the wood itself. If you’re applying a new stain over an old one, choose a color that’s similar to or darker than the original. Test the color in an inconspicuous area to ensure proper color. 
• Coverage varies depending on the type of surface and type of stain. A general deck stain recommendation: Two thin coats are better than one thick coat.