Do I Need to Use a Primer to Stain a Wood Deck?

Don't Use a Primer on a New Deck

• The lumber on your new deck is naturally beautiful, and most people don't want to obscure its natural color and grain behind a heavy coating. There's no need to use a primer at this stage of your deck's life. If your new deck is constructed from pressure-treated wood (PTW), the recommended choice would be wood toner or wood preservative clear sealer. The wood toner supplies pigments that shield the fresh lumber from UV damage while hardening its skin. The clear wood preservative protects the wood from rot caused by moisture damage.

Don't Use a Primer Under Semitransparent Stain

• Depending upon how much your deck is exposed to sunlight and precipitation, you should switch to a semitransparent stain in a deck's second or third year. A semitransparent stain contains more pigments, which add color to the wood and protect it from splitting, cracking and warping from the effects of prolonged outdoor weathering. You do not need to use a primer under this type of coating, but you want to refinish your deck every two to three years for this treatment to be effective.

Use a Primer Before Applying a Solid Color Stain

• Most people wait until their deck wood has deteriorated before applying a solid color stain. When the wood appears dry, cracked or split, the original grain structure might no longer be apparent. The solid color stain will continue revealing the natural texture of the wood while providing additional protection from the elements. A primer will extend the life of a solid color stain by hiding the old stains, binding surface peeling and improving adhesion for the new finish.

The Right Types of Primers

• Do not use a primer that is meant for ordinary painting because it will mask the texture of the stain and could accelerate wear from foot traffic. You can choose between pigmented deck primers and clear deck primers. A primer for deck stain will penetrate into the wood and help the solid color stain adhere to difficult surfaces. This means that a wood deck primer should offer a higher adhesive content than most paint primers.