Yes, you can and should paint or stain pressure-treated wood, as this helps prevent the surface from cracking. However, it is crucial to wait for the wood to dry out completely from the chemical treatment process before applying a finish. If the wood is still wet, the paint will not adhere properly. The drying time can range from weeks to six months. To test if the wood is ready, drip some water onto a board. If the water is absorbed, the wood is dry enough for painting or staining. If the water beads up on the surface, it needs more time to dry. You can build with the wood while it's still wet, but you must wait for it to dry before painting.

It’s best to use an exterior latex acrylic paint to promote maximum adhesion to composite decking. This flexible paint type can better cope with the natural expansion and contraction that can occur with composite deck boards. Oil-based paints won’t adhere as effectively and are more likely to crack and peel as the boards flex. Testing whether your chosen paint will stick on an inconspicuous section or a spare board is a good idea.

A wood deck requires annual cleaning and regular inspections for loose or broken boards, nails, and screws. It should be refinished by applying a stain or sealer every two to three years to protect the wood from water damage, rot, mildew, and sun fading. The exact frequency can depend on the climate and the deck's exposure to sun and moisture. If your deck is painted, it will need repainting approximately every 10 years. Signs that your deck needs refinishing include faded, splintering, or warping boards.

It is not always necessary to remove old stain before restaining a deck. If the previous stain is in good condition and is compatible with the new stain, you may be able to apply a new coat after thorough cleaning. However, if the old stain is in bad condition, flaking, or peeling, it is best to remove it completely to ensure an even surface and proper adhesion for the new coat. Staining over a damaged layer can lead to an uneven finish and poor penetration. For best results, test a small area first and consult the stain manufacturer's guidelines.