Pressure-treated wood is incredibly hardy, but it doesn’t last forever. Its surface can become gray and splintery, accelerating the weathering process. Or the reddish-brown or natural tone of new pressure-treated wood may not suit a homeowner or do-it-yourselfer who wants a more vibrant color. Painting is a great option for brightening the wood and helping it last longer.
Can You Paint Pressure-Treated Wood?
Pressure-treated (PT) wood has a copper azole liquid compound injected into the wood under high pressure. Copper helps to preserve the wood.
Pressure-treated wood can be painted using a brush, roller, or sprayer. Before painting, the wood must be dry both on the surface and internally. A high-quality, water-based exterior latex paint, along with a corresponding primer, is the best paint to use on pressure-treated wood. Do not skip the primer; paint needs the primer to help with adherence.
In contrast, before applying stain, pressure-treated wood only needs to be dry on the surface—not necessarily inside. The distinction is important because some wood coatings, like stains, are breathable. Other coatings, such as paint, lock in moisture. If pressure-treated wood is painted too soon before it’s fully dry inside, the paint is likely to peel, and the board could warp.
Should You Paint Your Pressure-Treated Wood?
New pressure-treated wood is designed to be exposed to the elements; it needs no additional coating for preservation.
Climate, maintenance, project type, and wood species play into pressure-treated wood’s lifespan. Pressure-treated pine, fir, or hem-fir that is kept relatively dry and maintained with water-repellant can last 20 to 40 years.
When pressure-treated wood’s copper treatment has lost its effectiveness, painting with exterior-grade paint is a good option to help with preservation.
Before You Begin
Painting over pressure-treated wood with high moisture content can result in the paint peeling, cracking, blistering, or changing colors.
Test the internal dryness of the pressure-treated wood with a moisture meter. For exterior wood, aim for moisture levels of 15 percent or less. If the pressure-treated wood is going to be used inside, it should be around 12 percent or less. For new pressure-treated wood, wait several weeks for it to dry adequately before painting.
Pinless moisture meters calculate internal moisture content with an electromagnetic sensor. Pin-style meters require tiny holes drilled in the wood. Meters can be rented, or they can be purchased for around $75 to $175.
How to Paint Pressure-Treated Wood
Source: The Spruce