How To Know If Wood Is Pressure Treated?

Pressure-treated wood is frequently used in many projects, but how can you recognize it? 

If you’re new to woodworking and want to get your feet wet, you’ll need to learn how to distinguish pressure-treated wood from conventional wood.

Learning to differentiate them will be useful in the long run, especially if you have to work on larger projects that require the use of pressure-treated wood rather than conventional wood.

How Can You Tell If A Piece Of Wood Has Been Treated?

Detecting if wood has been treated is no longer a problem, as most wood treatment businesses label their products to assist you in recognizing it, and to reduce any potential chemical contamination on people.

Another way to recognize it is by noticing the color and smell. Because of the treatment process, pressure-treated wood is either green or brown. Furthermore, treated wood can have an oily odor, as opposed to the pleasant natural scent of untreated wood.

What Exactly Is Treated Wood?

Pressure-treated wood, as the name implies, is wood that has been treated with chemicals while under pressure. During pressure treatment, the wood is placed in a de-pressurized tank to evacuate the air and replace it with preservatives that effectively preserve the wood against fungus, mites, insects, and rodents.

Although most treated wood is pressure-treated, it can also be surface coated. Surface coating means that the preservation chemicals are applied to the wood without being subjected to pressure, but by dipping, brushing, or spraying it. This is frequent when treating lumber or building components after they have been installed.

One popular myth is that treated wood is more water-resistant, however, this is not the case. Treated wood absorbs the same amount of water as untreated wood.

About Softwoods

Before you can identify whether a piece of wood has been pressure treated or not, you should become acquainted with softwoods and even hardwoods. Almost all pressure-treated wood is softwood, with the majority being coniferous trees including Douglas fir, yellow pine, white pine, and spruce.

Softwood trees generate lumber that is inherently wetter than hardwood trees because softwoods contain far more sap than hardwoods. The presence of extra sap in softwood explains why softwoods require pressure treatment to extend their service life. Furthermore, the natural sap routes allow chemicals from pressure treatment to penetrate deeper into the wood’s cells.

As a result, if you look at wood and notice that it is a hardwood, it is quite likely that it has not been pressure treated.

Now, let’s discuss more in-depth the several methods you can use to make sure you are purchasing the correct type of wood for your next project.

Look For An End Tag

Examine the piece of lumber to check if it has a stamp or label indicating that it has been pressure treated. An end tag on treated wood should include the name of the preservative used in the treatment, its rating, the preservation company, and any other pertinent information.

If you come across any wood that has been treated with Chromated Copper Arsenate (CCA), avoid it at all costs. This specific preservative contains arsenic, which is thought to raise the risk of cancer. CCA-treated wood is not permitted for use in decks, playgrounds, or other residential buildings.

Obtain A Fact Sheet

If the lumber you’re going to buy doesn’t have a tag, you should request a fact sheet from the vendor before proceeding. The fact sheet should state which chemicals were used in the manufacturing of the lumber. If the lumber contains both Copper and Tebuconazole, you can be sure it is pressure-treated wood.

Locate The Stamp

A stamp should indicate the sort of wood your dealing with and where it should be used. The safest type of pressure-treated wood is branded with an “FDN” stamp. When it comes to building the base below home flooring, this type of wood is preferred by many builders.

Also, wood that has been pressure treated with borate is suitable for interior use in homes and does not affect humans. Look for the stamp with the acronyms “Bor,” “Hi Bor,” and/or “Tim Bor” to identify borate-treated lumber.

Examine The Wood’s Color

If the wood you’re looking at doesn’t have an end tag, you might be wondering how to tell if it’s been treated. One of the simplest methods to tell if the wood has been pressure treated is to carefully examine the color; if it has a subtle olive-green color, it has been pressure treated. A borate-treated wood, on the other hand, will have a blue color.

Most builders and do-it-yourself woodworkers choose to use borate-treated wood in their homes because it is resistant to termites. Even though this wood is deemed safe due to low levels of toxins, it is not suitable for open use, particularly in outdoor locations.

If your wood is too old and weathered to see any color other than gray, you can cut a piece of it at an angle to view the hue.

Perform The Smell Test

If you can’t see any stamps or end tags, and you’re having trouble identifying any blue or green tint on a wood surface, you can pick up a chunk of wood and sniff it deeply. If the wood has not been treated, it will have a nice, fresh, natural odor. The majority of pressure-treated timbers have an oil or chemical odor.

Chemicals Used In Wood Pressure Treatment

Wood treated before 2003 includes a compound known as Chromated Copper Arsenic. This chemical is now deemed hazardous, despite being the most effective compound for treating lumber. It has UV resistance, which protects the wood from discoloration and other problems.

Copper azole is another great wood preservative; it is minimal in toxicity and does not affect the soil even if its elements go into it.

Copper Naphthenate is another substance used to treat timbers such as fences, greenhouses, railroads, and so on. It is ideal for woods that come into contact with the ground or water.

Borate is one of the safest chemicals to use in wood pressure treatment because it is non-toxic to both the environment and humans. Its components inhibit the growth of molds and fungi.

Creosote preservative is suitable for wood types that are primarily used for industrial purposes alone, such as railroads because it contains a significant amount of coal.

What Is Pressure-Treated Wood Used For?

So you know what to look for when purchasing pressure-treated wood, but what is its intended use? Pressure-treated wood is commonly used for decks, picnic tables, and light posts. Some people prefer to utilize pressure-treated lumber over conventional timber since it is less expensive and usually more durable. As a result, you are less likely to need to spend money on repairs in the future. Also, treated wood can be painted or stained to better suit your project as explained in this article.

Some Safety Recommendations

When it comes to identifying pressure-treated wood, there are a few things you should be aware of in order to operate safely with it. As wonderful as pressure-treated wood may be, the preservation chemicals utilized are extremely hazardous to both the environment and humans.

The pressure-treated wood preservative is meant to adhere to the wood, however, it can filtrate over time. So, here are some of the most important things to remember while working with pressure-treated wood.

Wear Safety Equipment

When working with pressure-treated wood, you should always wear gloves and long sleeves, as well as a dust mask when sanding or drilling. This will protect your skin by limiting your exposure to the pollutants.

Clean Your Hands

When you’re through working with pressure-treated wood, you must immediately wash your hands. You don’t want to eat with unwashed hands after dealing with pressure-treated wood.


When using bleaching products, exercise caution. They have the potential to cause the wood to emit poisonous compounds that are dangerous if inhaled.

Cutting The Wood Outdoor 

Never cut pressure-treated wood in a confined space. Always cut pressure-treated wood outside or in a windy location.

Burning Treated Wood

Never light a fire using pressure-treated wood. When pressure-treated wood is burned, hazardous compounds are released and can be deadly if inhaled.

Allow Time For Drying

When working with pressure-treated wood, always allow it to dry completely before staining or painting.

Final Thoughts

As you can see, determining whether or not wood has been pressure treated is not as difficult as it may appear. While it is true that experience is quite helpful, if you are a newbie, now you should be able to tell it apart from conventional lumber.

Most of the time, reading the tag at the end of the wood should be sufficient to determine whether or not it is pressure-treated wood, or you may need to get a fact sheet from the seller in order to read the chemicals used. Still, the process is rather basic and straightforward.