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Can You Bury Pressure Treated Wood? (Read This First!)

Woods are most easy to shape and one of the less expensive materials to work with for any project. If you talk about durability and longevity then there are several 800 to 1200-year-old wooden pagodas in Japan that have survived several massive earthquakes and typhoons.

But even with the modern treatment, protective coating, why does our fence or any wood bury underground rot so quickly? Let’s find out more.

Can you bury pressure treated wood?

It is possible to bury pressure-treated wood. However, if the wood is not properly sealed, its longevity while buried might be severely reduced. Moisture, vermin infestation, and other problems must be avoided while burying wood. The quality of the pressure-treated wood will also be crucial.

You can surely bury pressure treated wood. But it may vary according to the pavement and its material. Lets get to know them.

In concrete:

Pressure-treated wood buried in concrete will have almost 50 to 70 years of longevity. The concrete provides a solid protective barrier against moisture, rainfall penetration, and helps add a few more service years on the wood.

Concrete has a solid impenetrable quality, that means even air can’t pass through it. So pressure-treated wood buried in concrete won’t be affected by any sort of disturbance.

However, even after being buried in concrete, if the pressure-treated wood has any sort of contact with soil, it will surely receive a significant amount of moisture, hence it may start to decay. 

Burying pressure-treated wood in concrete is quite expensive and there are several other steps such as pre-casting the concrete slab and chamber, filling up any sort of getaway for moisture, sealing, and many more.

So you need to be dedicated and have a clear estimated idea before burning the pressure-treated wood in concrete.

In dirt:

Burying pressure-treated woods in the dirt may be the cheapest but it possesses a high risk of completely decaying the woods.

Natural soil doesn’t provide any protection against moisture, rainwater can easily penetrate through and reach anything buried under. It’s also easy for bugs and animals to dig through the dirt.

So lots of precautionary steps are needed to follow for preserving the pressurized woods properly. Burying woods in dirt has been a pretty old practice and it does provide somewhat satisfactory results.

If proper procedures are followed, pressure-treated woods buried in dirt may stay in tip-top shape for almost 30 to 50 years.

Will pressure treated wood rot if buried?

If pressure-treated wood is buried, it is not certain that it will decay. Certain parameters must be satisfied before any type of degradation may begin. Buried pressure-treated wood only starts to rot in the presence of an ample amount of moisture.

However, it can be easily avoided if proper preservation methods are applied. The rotting of pressure-treated wood is also affected by the environment in which it is buried. If it’s buried on damp soil then it will decay faster than usual.

On the other hand, if the wood is buried in concrete then it may stay intact for almost a century. So you can say, pressure-treated wood won’t rot just because it’s buried.

Wood quality, buried environment, the moisture content will always be the dominant and determining factor.

It may seem surprising but you can even keep pressure-treated wood underwater just by following the proper sealing process. So adequate knowledge and dedication are a must for getting the best out of pressure-treated wood.

What happens when you bury treated wood?

Certain treatments are done to make the wood preserve itself from any sort of decay. Just burying it won’t make any difference if the treatment was good enough.

Chemical treatment, pressure treatment, fire retardant coating, and several other types of treatment are normally followed, you need to choose the suitable one for your project. One of the major concerns about burying the treated wood is the decaying.

We have seen woods literally underwater and been in good condition for decades and we have also seen treated woods buried in soil starting to decay in months.

When the protective layer fades away the wood becomes vulnerable to fungus build up, pests start to bite and destroy the integrity of the wood.

You may also see the opposite picture if the protective layer is still intact on the surface of the wood, it may last for almost half a century buried in the ground and still show remarkable durability.

Putting the treated wood underground may be a huge concern as we can’t do visual inspection nor know about the overall state, so the pre-burying precautionary steps will determine the fate.

How long will buried pressure treated wood last?

In an ideal condition, buried in the dirt a pressure-treated wood will last almost 30 to 50 years. If the wood is buried in concrete then you can expect 70 to 80 years of service period out of them.

If the treated wood is buried underwater then it may stay in good shape for almost 25 to 30 years. You need to make sure that you have chosen the right quality wood for the specific environment.

The pressure-treated wood is made for multipurpose use but when you bury it underground, the protective layer may wear out, the soil moisture may take over and ruin the integrity of the wood.

Let’s assume you have buried the pressure-treated wood in concrete, with no chance of getting in touch with soil moisture but the wood may still decay due to poor wood quality, avoiding moisture sealing, and many more.

How to bury a pressure treated wood? 

To bury the pressure treated wood you need to follow some steps to give it a longer life. Let’s dig in below to know about them.

Dig deep:

Digging a deep hole can certainly help you with your decaying problem. The lower you go the harder it becomes for the air to reach. If there is no air then fungus won’t survive and bugs or any other animals won’t bother to dig down that low.

Choose the suitable grade:

The grade of the wood can determine how durable it is. Pressure treatment is done for making the wood decay proof but different types of woods react differently under pressure treatment.

For some, it may last long, for some woods it may wear out even in a bit harsh condition. Marine-grade or woods with 0.60 grade will be the best choice. If it’s out of your budget then try avoiding a 0.25 grade and try something from the higher grade.

Moisture sealing:

Applying Moisture sealing before putting the wood underground will certainly add on an extra layer of protection against rotting.

How do you protect pressure treated wood underground? 

There are few precautions you need to make sure to give the pressure treated wood a longer life. Check below to know them.

Make it a no oxygen zone:

Every living organism needs oxygen to survive. Most tree fungi need oxygen to survive, so you need to use it for your own advantage. Try to work with a big size of lumber, dig a foot deep and try your best to air seal the hole.

Putting rock, sand, plastic cover, or burying concrete can always ensure this airtight condition. Even if the chemical wears out or the soil becomes ridiculously wet, you won’t need to worry about decaying anymore. 

Moisture sealing: 

If making the ground airtight isn’t possible then moisture sealing is your best bet. Most fungi thrive in the presence of moisture, and wood buried in the dirt will certainly receive moisture from the rainwater or the moisture stored in the soil.

Applying Moisture sealing individually or along with making the underground environment airtight will certainly bring fruitful results.

Paint them:

Painting the woods can certainly help fight against rotting. Paint will help fend off any moisture from getting through, fungus will have a hard time attaching and penetrating through the paint.

Temperature control:

This is quite hard and almost impossible to do but your effort can bring fruitful results.

You can make an inclined surface for the surrounding of the woods, which will make sure no rain or surface water stays too long to put any adverse effects. You can shovel away the snow to keep the temperature in control.

The moist and damp atmosphere along with the low temperature is breeding heaven for fungus. If you can somehow keep the temperature under control then it’ll be hard for the fungus to grow.

Chemical treatment:

It’s kind of a last resort for some. Using chemicals to treat the woods may solve your decaying problem but it may put a negative effect on the environment.

If you are putting the wood near a water source or near vegetation, the chemical components may spread and pollute them. So keep that in mind before applying any additional chemical to the woods.

Final Thoughts 

You can surely bury pressure treated wood, but the required precautions must always be taken to keep it secure. Even in the worst-case scenario, buried pressure-treated wood can last 10 to 20 years, but the quality, durability, and appearance will go through a lot.