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
Equipment / Tools
- Paint roller
- Roller cover with 3/8-inch nap
- 5-gallon bucket
- Roller screen
- Putty knife
- Brush with nylon bristles
- Moisture meter
- Exterior primer
- Exterior paint
- Two-part moldable epoxy resin kit (optional)
- Two-part epoxy wood consolidant
- Oxygenated cleaner
Use a nylon-bristle brush and an oxygenated cleaner or deck brightener to remove dirt, mold, and mildew from the surface of the pressure-treated wood. Areas closer to the ground get dirtier due to splashing. Sections of the wood facing away from the sun are more prone to mold and moss growth.
Test Moisture Content
After the wood has completely dried from cleaning, use the moisture meter to test the pressure-treated wood's internal dryness.
To test external dryness, do the water sprinkle test. Sprinkle a few drops of water on the surface of the wood. If the water quickly soaks in, the surface of the wood is dry enough to be painted.
Brush Primer on Wood
Pour the primer into the 5-gallon bucket and add the roller screen to the side (inside of bucket). Use the brush to prime narrow, recessed, or high areas that the paint roller will not reach.
Roll Primer on Wood
Switch to using the roller for large and flat sections. Paint by first dipping the roller cover in the primer, then rolling it out on the screen. Move the roller to the pressure-treated wood. Roll in small sections of about 4 feet by 4 feet. Take your time and work slowly.
Brush Paint on Wood
Let the primer dry for 30 to 60 minutes. Clean out the paint bucket and roller screen. Add paint to the bucket and stir thoroughly. As with the primer, use the brush to address areas that the roller will not fully reach.
Roll Paint on Wood
Use the paint roller with a fresh roller cover to paint the wood. Apply one coat, then allow it to dry. Paint recoat waiting times can be as little as a half-hour for flat paint and up to three hours or even more for a glossy paint. Apply the second coat when dry.
When to Call a Professional
Small-scale painting projects are manageable by most do-it-yourselfers. But large-scale projects, such as painting a deck or fence, may require the assistance of a professional painting company.
Is it better to stain or paint pressure treated wood?
Staining pressure-treated wood is easier than applying paint. Stain grabs onto pressure-treated wood better, while the paint is a little more difficult to adhere, often resulting in peeling if the wood is not fully dry or ready for painting.
Is it OK to sand pressure-treated wood?
You can sand pressure-treated wood, but it is not recommended. Since wood is chemically treated, sanding those chemicals can affect your health and the environment. Also, not all pressure-treated wood is the same, so it can look very inconsistent after sanding.
Does pressure treated wood turn gray?
Overview of Wood Preservative Chemicals. United States Environmental Protection Agency.
Lebow, Stan, et al. Long-Term Durability of Pressure-Treated Wood in a Severe Test Site. Advances in Civil Engineering Materials. 2013;2(1):178–188. doi:10.1520/ACEM20120054