How to Paint Pressure Treated Wood
What is Pressure Treated Wood?
Pressure-treated wood is when chemicals used to preserve the wood are infused in it. The wood is placed in a vacuum cylinder. Once it is in the vacuum, all the air will be drawn from it, and the wood will be dried out. The cylinder is then filled with preservatives at a high pressure to force the chemicals deep in the wood. This whole process is controlled by a computer. The wood is then removed from the cylinder to dry. Afterward, it will be given a topcoat or be used in a manufacturing context.
Pressure-treated wood is necessary for outside building projects, especially if the wood is going to be in contact with the ground. The chemicals in the wood help to prevent rot as well as repel insects. Preservatives in the wood also prevent it from being susceptible to moisture which can make the wood soft. It is advised not to use pressure-treated wood in areas where it could come in contact with food or around children. It is not necessary to use this type of wood in the home.
For a long time, chromated copper arsenic (CCA) was used as a preservative when treating wood. However, the chemical is extremely toxic which led to the EPA’s need to monitor companies that use CCA. Although CCA is generally safe, it is recommended that homeowners, every few years, apply a penetrating oil finish. This will lock in the dangerous chemical. The production of residential CCA was discontinued in 2003 due to public pressure. Alkaline copper quat (ACQ) is the most popular alternative to CCA. Many insects and fungi find copper to be toxic and cause decay in these organisms. ACQ adheres very well to wood fibers.
If you are looking for an alternative to pressure treatment, there are a few options. Cedar and Redwood are naturally more resistant to rot than other types of wood. You can use non-toxic wood sealant as well as good enamel to protect your wood. Washing your timber with lime and water can also give your wood some protection. Pressure-treated wood also needs to be coated with a sealant to protect from corrosion.
Can Pressure Treated Wood Be Painted?
Pressure-treated wood can be painted with latex paint. Oil-based paint should be avoided as it will resist the surface of the wood. Some people may choose to stain their wood. However, there are benefits to painting it instead. Paint increases your color choices infinitely. You can also replace a previous color with another one. Paint is good for filling gaps and cracks. Paint can be used for repairing wood. High-quality paint can create a hard shell which makes the wood easier to clean. Paint also lasts longer than a stain.
There are few reasons why someone may forego paint for stain. Stain shows off the beauty of the wood. It is less slick when wet which makes it less dangerous. Also, if you stain your wood, you can always paint it later on down the road. Once you decide to paint your pressure-treated wood, you can’t go back and change it for a stain unless you are willing to go to extreme measures.
There are a few ways to remove the paint. You first need to sand the paint off with 75 grit, or lower, sandpaper. Work the sandpaper in a circular motion against the wood. It is also possible to use an orbital electric sander which will sand the surface evenly. You can also chemically strip the wood. Put on gloves before doing so. Add the chemically stripping agent to the wood with a rag or sponge. Leave the agent on the wood for the recommended time, and then wipe it off. Once that is done, leave it to dry. Another way to remove the paint is with a heat gun. The heat gun will loosen the paint which you can scrape off with a metal scraper.
How to Paint the Wood
Usually, when you pick up wood from the timberyard, it isn’t fully dry. Wood also needs to be cleaned before it can be painted. It may seem like an unnecessary step, but wood collects dust and debris during transport to your residence or location of the building site. Use a stiff brush and soapy water. Clean with the grain. You should build with the wood right away or stack it in a safe place to dry. It is important to have the wood dry before painting it. The moisture level should be below 15%. This process can take four to 120 days. It may be possible to rent a moisture meter from your local hardware store. It is also possible to pour water on different sections of the wood. If the water is absorbed by the wood, it can be painted. It is also possible to buy Kiln-Dried After Treatment (KDAT) wood. KDAT wood is when the pressure-treated wood is placed in a heated container to dry. This lessens the risk of wood warping.
Use stickers, thin wood pieces slightly wider than the pressure treated wood, when stacking the wood. You can also use paint stirring sticks. The sticks give the wood airflow which helps with drying. Is also keeps the wood from warping. All stickers or sticks should have the same thickness. Stickers should be placed on the ground under the wood and spaced four feet apart. Put stickers on the wood and repeat the process until all the wood is stacked on each other.
All painting should be done during warm, dry weather when there is low humidity. It is important to apply primer to your wood because it is very difficult for paint to adhere to pressure-treated wood. If you have a lot of knots in your wood, apply a knot sealer before you add the primer. Not sealing up the knots can lead to sap seeping out and bleeding through the paint. Pick a primer that is specifically for outdoors and pressure-treated wood. Other primers will not last as long since the wood is liquid-resistant. You can choose from two types of primers. A latex primer is water-based. It also dries fast and is less susceptible to cracks when under pressure. It is typically better at priming pressure-treated wood than the other option. The other type of primer is oil-based. An oil-based primer takes longer to dry. It also gives off fumes. Apply the primer according to the directions on the label of the primer. Thin coats are more evenly spread and dry faster than thick coats. It should take two days for the primer to dry. When painting the wood, apply at least two coats of latex paint.