How to Stain a Pressure Treated Wood Deck

A pressure treated wood deck needs special consideration when staining or sealing it. Pressure treated wood has preservatives (including arsenic) that are forced deeply into the wood fibers to protect against rot, mildew, and termites. Pressure treated wood is one of the most preferred materials of deck builders and homeowners alike for this very reason, and are, therefore, very common. Because the wood is altered, you have to be particularly careful when staining or finishing it. Here you will find the information that is needed to stain a pressure treated wood deck.

Step 1 - Cure the Deck

Pressure treated wood takes about two months to "cure" after it is installed before it can be stained. Allow your deck to cure an appropriate length of time before you attempt to stain or seal the material.

Step 2 - Clean the Deck

Clean the deck of any debris or dirt before staining. If this is an existing deck, a pressure washer can be used to clean the wood and prepare it for staining. Be careful with the pressure washer, as it can damage the wood if the pressure is too high. Start with a psi level of about 1,500 and work your way up from there, monitoring carefully to ensure the wood isn't getting chewed up. Allow the deck to dry at least two days before staining it. It should be completely dry before staining.

Step 3 - Prep Surrounding Structures

Oil based stain is very thin and is easily splashed or sprayed on bushes, structures, and underlying materials inadvertently. Cover the underlying concrete pad, surrounding bushes, or grass with tarps to protect them from getting inadvertently splashed, dripped on, or sprayed.

Step 4 - Apply Stain

Overall, applying stain with a paintbrush will give the best results. The brush serves to work the stain into the wood grain, and the result is a more even look. You can, however, use a roller to apply the stain (in which case you will still need to use a brush for small, tight spaces) or a sprayer. While both of these are much more efficient than a brush, neither will achieve the quality of finish that a brush will. Make sure to read the instructions on the particular stain you are using for any product specific application instructions.

Step 5 - Test the Seal

A second coat can be applied after the first is dried. The best way to tell if the deck needs another coat is to spray some water on it. If the water is absorbed by the wood, it is not sealed. Add another coat. If the water beads, there is a good seal on the wood. Make sure that another coat is applied the following year to maintain the integrity of the seal.