Working with pressure treated wood can be a little different than using untreated wood, and it’s important to know what you should and shouldn’t do. Getting good results with pressure treated wood requires understanding the unique properties of this type of lumber.
Painting is an area where pressure treated wood definitely isn’t the same. If you try to paint pressure treated wood too soon, the paint will slough off the surface of the wood. It’s absolutely possible to paint pressure treated wood, but you need to make sure to follow the correct sequence to make sure the paint sticks and looks good.
What is Pressure Treated Wood, and What Happens if You Paint It Too Soon?
What is pressure treated wood and how is it made? Pressure treated wood is wood that has been injected with chemicals in order to make the wood resistant to rot, fungus, and insect damage. Using a pressurized vacuum sealed tank, a solution of chemicals (commonly including chromium, copper, and arsenic) is forced deep into the wood’s interior.
These chemicals make the wood inhospitable for the species of insects like termites and ants that frequently eat or burrow through wood, and also make the wood less susceptible to natural rot and decay.
The chemicals used in the pressure treatment are water borne, and most pressurized wood is shipped and sold in a ‘wet’ condition. This means that the water component of the chemical solution is still active in the wood, and over time that water needs to leach out of the wood and dry.
If you paint pressure treated wood too soon, the paint is going to be rejected by the wood as traces of the chemicals and the water works its way out of the wood during the drying process. Your paint will peel off within weeks of your applying it.
How to Paint Pressure Treated Wood
The most important step to painting pressure treated wood is letting the wood dry appropriately. This may take a few weeks up to as long as a month, depending on how ‘wet’ the wood was when you bought it.
One of the biggest indicators of the state of pressure treated wood is its color. When the wood is wet, the color will be a dark, greenish hue, but over time it will soften to more of a light greenish-brown. To be on the safe side, give yourself a month before attempting to paint the wood.
Like with painting any wood, it’s a good idea to wash off the surface with soap and water and allow the water to dry on the wood surface before painting.
Then, apply primer, followed by an initial coat and finally a top coat of paint like you would in any painting project.
Once you’ve dried out the pressure treated wood, the process is pretty similar to painting untreated wood, so make sure you heed that first step.
Is it Better to Stain or Paint Pressure Treated Wood?
If you prefer staining to painting, you’re able to stain pressure treated wood as well as painting it. In fact, staining can sometimes be a superior option to painting, as the stain is slightly easier to apply and soaks into the wood’s surface.
The downside to staining is that the color options are considerably more limited than painting, just like when dealing with untreated wood. And painting is able to fill in some of the imperfections and cracks on the surface of the wood in a way that staining doesn’t.
If you plan on staining pressure treated wood, make sure to follow the same initial sequence as if you were painting. Allowing the wood to dry from its chemical treatment is essential, and the stain will similarly not stick if you apply it too soon.
What Kind of Paint Do You Use on Pressure Treated Wood?
Ideally, you’ll use a latex paint, also referred to as a water based paint. These types of paints are superior to oil-based paints for pressure treated wood.