Green pressure-treated wood is the wood commonly found in outdoor settings like electric poles, mailboxes, fences, and ocean boardwalks to name a few examples. This type of pressure-treated wood is sometimes referred to as “green” because of the chemical compound it is treated with, Alkaline Copper Quaternary, which creates a green hue. Since this wood is already treated, many wonder if it can be stained.
Although green pressure-treated wood can withstand various outdoor conditions and is protected against rot and insect damage, it does not always look appealing. You can stain green pressure-treated wood and it is recommended to do so as some stains add further protection like water resistance.
While you can stain green-treated wood, there are certain stains to use based on how the wood was treated and it helps to know the basics of green pressure-treated wood.
- 0.1 What Is Green Treated Wood?
- 0.2 What Happens if You Stain Pressure Treated Wood Too Soon?
- 1 What Kind of Stain Should I Use on Pressure-Treated Wood?
What Is Green Treated Wood?
Green treated wood, otherwise known as pressure-treated wood, is wood that has had preservatives forced into it under pressure to make it resistant against decay and insect infestations. You will notice that freshly pressure-treated wood has a green hue and this comes from the preservative, Alkaline Copper Quaternary, that is used to treat it. Over time, with exposure to outdoor elements and sunlight, the green hue fades to grey.
Pressure-treated wood is rated based on the amount of chemical retention it has including, above ground contact, below ground contact, and ground contact. It is important to know the chemical rating of the treated wood you plan to use to ensure it will best suit the job you need it for.
What Happens if You Stain Pressure Treated Wood Too Soon?
Curious to how soon you can stain pressure-treated wood? In some cases, pressure-treated wood is sold before it has fully dried all the way through. If you try to apply a stain to it before it has fully dried, the stain will not saturate the wood well enough to enable its protective qualities. Once fully dried, you can stain your lumber with water or oil-based stain depending on what it was treated with.
There are three types of treated wood available and knowing which one to buy can help you with the timing and decision to stain it.
Wet Treated Wood
This type of treated wood is still wet when you purchase it. You will notice that it will be heavier than the other treated types of wood due to the moisture that is present within it. Depending on the climate you live in, you should let this type of lumber dry out for a few weeks up to several months before applying any stain to it.
Treated Wood with Water Repellent
Some manufacturers add water repellent to their treated wood as an added layer of protection. If you choose water repellent wood, you can only use an oil-based stain on it, as water-based stains will not adhere well to it.
Kiln Dried Pressure Treated Wood
This is the quickest and easiest type of pressure-treated wood available because it has been treated and fully dried before purchase allowing any stain to adhere to it effectively. You will want to look for the rating KDAT (kiln-dried after treating) or ADAT (air-dried after treating) to ensure you are purchasing pre-dried pressure-treated wood.
What Kind of Stain Should I Use on Pressure-Treated Wood?
There are water or oil-based stains available for wood and which one you choose depends on what your wood was initially pressure treated with. To be safe, it is recommended to use an oil-based stain regardless of the treatment to allow for proper penetration into the wood.
While you can use a water-based stain on completely dried wood, you have to be quite careful to ensure the initial treatment did not include water repellent as this would inhibit its ability to saturate the wood, minimizing its protective qualities.
Whether you use an oil or water-based stain, you must be sure that the wood you are using is rated as kiln or air dried to ensure it is dry all the way through. If it is not completely dry, neither stain will stick to the wood well enough to be effective.
Ready Seal Exterior
Ready Seal Exterior Stain is available in two sizes and comes with multiple finish options. When applied it appears dark but fades to its true color within 14 days. This stain can be applied with a sprayer, roller, or brush and should not be applied to a previously stained surface for the best effect. The formula of this stain makes the wood water and UV resistant elongating its lifespan.
Thompson’s Water Seal comes in the color, Acorn Brown. This stain is water-resistant, mildew resistant, and minimizes UV damage to the wood. The finish of this stain is relatively transparent allowing for most of the natural wood grain to show through once set. You can also find Thompson’s WaterSeal on our recommended products for sealing untreated wood for outdoor use.
How Long Does It Take for Exterior Stain to Dry?
How long it takes exterior stain to dry is dependent on a few factors such as the type of stain used, the type of wood it is applied to, and the humidity levels where you are located. Typically, porous wood requires more time to dry as more coats need to be applied for an even coating.
Water-based stains dry somewhat faster than oil-based stains however water-based stains are more likely to be affected by high humidity and moisture like rain. If you are located in a humid climate, the stain will likely take longer to dry.
On average, the drying time of exterior stain is 24-72 hours. Please note that the color of the stain may continue to develop with exposure to outdoor conditions in the following weeks after application.
Can I Paint Green Treated Wood?
Yes, you can paint green treated wood however, like staining, there are a few factors to take into consideration to make sure the paint effectively coats the wood.
Pressure-treated wood must be completely dry (all the way through) before it is painted. Be mindful of the type of treated wood you purchase and dry it out before painting if necessary.
The most compatible type of primer and paint for pressure-treated wood can be found in our detailed exterior paints article following the link here. After ensuring the wood is dried through, you can apply a coat of latex primer then allow it to dry. Once the primer has dried, you can apply one or two layers of paint to your desired aesthetic allowing drying time between the coats.
Painting Pressure-Treated Wood Compared to Staining It
Because of the repelling qualities of the preservatives used to pressure treat wood, paint is hard to maintain on its surface and is likely to peel off. This is more so the case if the wood was not completely dry before painting. Painting pressure-treated wood also requires primer and additional steps to clean and dry the wood before painting in comparison to staining.
For this reason, it is recommended to stain pressure-treated wood instead of painting it if possible. As long as the wood has been kiln or air dried well, stain penetrates the wood’s surface with relative ease and has additional protective qualities to maintain the health of the wood.
Green pressure-treated wood has been a useful innovation for protecting and strengthening wood against outdoor elements, increasing its lifespan. It is also possible to stain or paint pressure-treated wood to increase the protection of the wood and to enhance its visual appeal.