Will termites eat pressure treated wood? A Detailed Review

The use of pressure-treated wood has been around for over 7 decades. However, very few people are aware of this type of construction material. Is it because we generally think that wood is less durable and, therefore, we don’t consider the available options? Or is it because we normally don’t handle most of our constructions?

Termites love to feed on wood material and that’s why some manufacturers opt for pressurized chemical treatment options. Below is an overview of the relationship between pressure-treated wood and termites.

Do termites prefer untreated wood to pressure-treated wood?

Well, termites prefer untreated wood. If they were to attack pressure-treated wood, their chances of success are much lower. This is because such woods contain chemicals that make them stronger and more durable. The presence of toxic chemicals also repels them away.

On the other hand, untreated wood attracts these insects due to the presence of cellulose. This is an organic compound that they mainly love to feed on. Termites are highly destructive insects and they feed on both hard and softwood.

What about pressure-treated wood deters/attracts termites to it?

Pressure-treated woods usually contain chemicals that deter or are toxic to termite insects. The process involves the use of a vacuum cylinder and chemicals.

For starters, the wood material is normally placed inside the vacuum. Thereafter, the air is completely drawn from it, leaving only dry timber. Lastly, the vacuum cylinder is filled with the appropriate preservative usually channeled at high pressure for forced deep penetration into the wood.

Once the treatment is over, the wood is left to dry before the manufacturer adds a topcoat. The effectiveness of such a treatment option is based on the fact that it treats the entire timber, making it less susceptible to parasites, rot, and insect attacks such as termites.

The traditional chemical used in this kind of wood treatment was chromated copper arsenate. However, it was phased out of the market due to its toxic nature. There were serious environmental and health concerns regarding the use of arsenic and chromium.

Other than arsenate, some of the environmentally-friendly chemicals that are used today include micronized copper quaternary, copper azole, alkaline copper quaternary, and sodium borate.

Currently, there is a wide range of inorganic materials and other chemicals that are used to pressure-treat woods. The best thing about these new chemicals is that they are less toxic and some of them even contain high levels of copper.

How Do Termites Eat Pressure Treated Wood?

Will termites eat pressure treated wood? Well, pressure-treated wood is not completely termite-proof, even though termites don’t damage them the way they do with untreated wood. There are three ways these insects can attack such wood and they include:

Incomplete wood treatment

In case the pressure treatment doesn’t fully penetrate to the middle part of large wood, then it will be susceptible to termite attacks. This is because its core will still be in a natural state. To minimize this, both ends of the wood can be treated or if possible, the planks should be made thinner.

The period under use

Pressure-treated wood is only durable for a certain period. So, once it elapses, then wood ends up becoming susceptible to termite attacks. It should be noted that elements of weather including moisture and rain usually strip the wood of the preserving chemicals as time goes by. Make sure that you carry out proper maintenance and replace the wood.

Note: the best pressure-treated wood for long-lasting use is usually rated “ground contact”. Its durability is enhanced by the higher amount of chemical treatment. So, it will resist a termite attack for longer.

Cut or Broken Edges

Part of the problem that leads to termite attacks is newly cut or broken edges. This mainly happens during construction fittings. Well, if the treatment isn’t deep, then the newly exposed parts won’t be protected.

Note: for better durability and minimal risk of termite infestation, the newly exposed wood needs to be treated onsite with a preservative.

Is there a way of protecting your pressure-treated wood from termites?

The best way to protect pressure-treated wood from termites is to seal and stain it. Sealing your pressure-treated wood and adding stain helps to enhance its durability, thereby reducing the chances of damage by termites.

Sealing and staining prevent the wood from unnecessary shrinking, expanding, and cracking. These are some of the loopholes that termites may use to attack the lumber due to increased weakness.

However, you need to ensure that your wood is fully dry before you start either of the two processes. To seal the wood, simply get the appropriate sealant that perfectly adheres to the wood material. You can handle this process by using a paint pad applicator.

A pad applicator provides a faster way of applying the sealant compared to a brush. Additionally, the pad is ideal for producing a cleaner appearance. This is because it normally creates an evened-out finishing. With sealing, only one coat is enough.

You can apply the stain using a brush, sprayer, or roller. Apply a coat or two and then leave it to dray. You need to give your wood at least two days for the stain to dry.

Make sure that you inspect the pressure-treated wood from time to time. However, pay special attention to the fixtures during summer and winter. These are usually extremely hot and cold seasons and they may easily affect the wood negatively. In case you notice any problem, carry the appropriate maintenance task as soon as possible to prevent further damage.

Why is Pressure-Treated Wood Popular?

Generally, wood is a valuable construction material. But it’s not highly durable because it’s prone to decay and attack by insects. This usually significantly reduces its use. To enhance its durability and flexibility, most wood varieties are usually pressure-treated. By what exactly makes this type of wood popular?

Insect Resistance

Pressure-treated woods are usually resistant to insects such as termites, carpenter ants, and others. These insects usually pose a significant risk to any type of wooden structure. They quickly bore through them, causing massive damage and leaving the wood weak.

However, if the wood is pressure-treated, insect damage can be reduced considerably. This is because the availability of the copper compounds enhances the quality of wood. Additionally, the availability of borate chemicals deters insects.

While such wood is durable and ideal for construction in insect prone areas, it can also be used for protective purposes. You can use treated woods to protect untreated wood by using it a barrier.

Ease of Use

The durability and characteristics of pressure-treated woods offer users ease of use. For instance, you can easily cut such type of lumber into pieces. Besides that, treated wood products are usually easy to fasten with nails because they are highly penetrative.

There is significant versatility in terms of shape and design. You can quickly and precisely drill holes or even use routers to shape them.

Available in Multiple Sizes

Such wood types are available in a wide range of sizes. This is because they are ideal for use in multiple areas of applications. For instance, you can get posts in several cross-section areas and types i.e. round or square cross-sections or in standard sizes such as 2×10, 2×6, or 2×4.

These sizes are available based on where you want to place the treated wood. Is it on the balcony, deck, fence, or a play-set for kids?

Fungal and Moisture Resistance

When wood is exposed to moisture, it tends to soften up. This makes it vulnerable to microorganisms that normally cause bacterial or fungal infections. Consequently, the wood ends up getting damaged and starts to slowly decompose.

However, pressure-treated wood materials contain strong chemical compounds that make them resistant to moisture. This normally prevents the growth of fungus and as a result, they are ideal for use in moist areas such as the basement region or underground posts.


Generally, pressure-treated wood usually lasts longer compared to natural wood. This is because natural wood can’t effectively withstand the elements of weather. Additionally, such wood isn’t resistant to insects, moisture, or fungal infections.

On the other hand, pressure-treated wood embodies durability. It can withstand various elements of weather and attack from damaging insects. This is because it’s usually denser and, therefore, has more strength so it can’t get easily oxidized.

Note: when using pressure-treated wood, use hot-dipped-galvanized or stainless steel nails, anchors, screws, connectors, and bolts. These are the only materials that effectively work with such wood material. Understand that new wood treatments have high amounts of corrosive chemicals that can destroy aluminum.

The Bottom Line

Pressure-treated wood materials are ideal for all types of construction. This is because they are durable, versatile, and resistant to termite attacks. The current types of chemicals used to pressure-treat wood are less toxic and environmentally-friendly. As a result, this makes treated wood suitable for use in different kinds of settings.

However, you should understand that pressure-treated wood isn’t termite-proof. The chemical preservatives wear off with time. Besides that, the core of the wood may not be fully treated. So, proper wood maintenance is still necessary.

Steve Foster

Mad about bugs and wanting to publish as many articles as I can to help educate people about these amazing beautiful creatures! For more info check out my about page https://schoolofbugs.com/about-steve-foster/

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