Yes, you can paint treated wood! But, the process of painting treated wood is not quite as straightforward as it seems.
This short article and video from The Honest Carpenter will teach you the tips you need to know in order to paint your treated wood projects more effectively!
(The following content contains some affiliate links.)
Suggested Tools & Materials:
These affordable synthetic filament brushes have an unbeatable price line!
Kilz Primer is the best primer on the market:
What Is Treated Wood?
“Treated wood” is a term used to describe wood that has been subjected to a chemical preservative process. Typically, treated wood is often the exact same type or species of untreated lumber that is available wherever you’re purchasing it.
Treated wood has been impregnated with waterborne preservative in a pressurized cylinder. These preservatives penetrate deep into the cellular structure of the wood, leaving behind a chemical residue that prevents fungi from infesting it.
(The chemicals used in the treatment process have been subject of some debate for the last thirty years. For a quick explanation of treated wood toxicity, check out our video about how to make raised garden beds!)
Can You Paint Treated Wood?
The answer is: YES, you can absolutely paint treated wood!
But, the catch is that you should not paint treated wood too soon after it has been purchased.
Treated wood is shipped while still “wet.” The liquid chemical preservatives are still present in the lumber, causing it to feel extremely heavy, and damp to the touch.
If you paint treated wood while it is still wet, your coat of primer or paint will most likely be rejected by the water-borne chemicals slowly bleeding their way out of the lumber.
So, how can you avoid this?
Give Treated Wood Time To Dry
Treated wood needs time to dry out slowly. This is a process that will occur naturally as the liquid preservative works its way back to the surface of the wood.
But, how quickly does this occur? It depends…
A variety of factors can cause treated wood to dry quickly or slowly. Exposure to heat and sunlight will often dry treated wood rapidly (but, this can also cause unexpected warp!) Damp and dark conditions can cause treated wood to stay wet for a long time.
Generally speaking, though, treated wood will dry out naturally in about 2-3 weeks.
Sometimes, pieces of treated wood will even lie on the lumberyard racks long enough to begin drying out on their own. Carpenters refer to this wood as being “shop dry.”
How Do You Know If Treated Wood Is Ready To Paint?
A quick test will usually let you know whether your treated wood is ready to paint.
Just dab a few drops of water onto your treated wood. If the water soaks into the wood pores, then the treated wood is dry enough to paint. However, if the water beads on the surface, you probably still need to wait a little longer.
Also, dry treated lumber will take on a light yellow-brown color. Wet treated wood, on the other hand, will be surprisingly green and dark.
How To Paint Treated Wood
Once your treated wood is dry, the painting process is very similar to painting untreated wood.
Always be sure to use a good exterior-grade primer on your treated wood first. (This layer of primer acts as an essential bonding agent between paint and lumber.)
Then, once your primer is dry, use a brush, roller or paint spray rig to apply even coats of paint to your project. Be sure to let each coat dry before the next is applied. And, if you can, lightly sand with 220-grit/extra fine sandpaper between each coat. This will create better paint adhesion!