Should You Use Pressure-Treated Wood In A Basement?

Disclosure: We may get commissions for purchases made through links in this post.

Wood is one of the most important structural elements in constructing your basement. You might wonder what the best lumber to buy is. To help you decide, we have done the research on whether you should use pressure-treated wood for your basement. 

If you really intend to use wood for your basement, you should use pressure-treated wood. Though a lot pricier than the conventional kiln-dried lumber, its long-term benefits cannot be understated. Pressure-treated wood has preservatives injected into it to ward off moisture, pests, and termites.

Though there are obvious advantages in using pressure-treated wood for your basement, it has also some drawbacks, too. It has drawn a lot of discussion and debate among wood experts on the safety and hazards of using treated wood indoors. Keep reading as we explore the reasons why pressure-treated wood is still the best choice for your basement.

Interior view of a house under construction home framing. Should You Use Pressure-Treated Wood In A Basement

Why Use Pressure-Treated Wood In Your Basement?

The use of pressure-treated wood is incorporated among the requirements of building code for home remodeling projects. Firstly, we need to know the mechanism of pressure treatment to the wood that makes it beneficial to your basement walls and flooring.

Advantages Of Using Pressure-Treated Wood

You can readily identify the lumber if it has gone through treatment. The numerous incision marks that line the wood grain represent the injection points where preservatives are forcibly injected into the inner layer of the wood. You can benefit from the following properties of high-pressure-treated wood:

High Resistance To Rot And Decay

Basement walls are usually constructed behind drywall.

In this setup, sunlight and air cannot fully penetrate, thus causing dampness and high moisture. This situation induces significant mold formation which could easily damage untreated attached wood. 

Using pressure-treated wood makes it highly resistant to rot and decay for a long period of time.

Read more: What Kind Of Drywall To Use For Basement Walls And Ceiling.

Absorbs Moisture From Basement Walls And Floors

Concrete and masonry walls, unless they are coated, are made of highly porous materials. Water can easily penetrate through, and dampness is most likely to happen. Wood, when in direct contact with concrete, rapidly decays. This is an inherent quality of wood and cannot be avoided.

Treated wood contains a preservative level of one-fourth of a pound per cubic foot. This volume is enough for use against concrete—both indoors and outdoors as well.

Additionally, when a wood post or column is resting against a concrete wall, the wood post should likewise be pressure-treated.

Since concrete is highly porous, moisture can still pass through capillary action. The treated wood can still absorb the water, but with preservatives injected, it could be resistant to rot and decay.

Similarly, how about the basement floorings?

Still, pressure-treated wood should be used for the bottom plate of any basement wall. This is because the treated wood can normally withstand some degree of exposure to water. If you want to know the ideal size of wood you need to use, check out this post: What Wood To Use For Framing A Basement?

close up photo of termites on decaying wood

Ultimate Defense Against Termite Infestation

Termites and other wood-boring insects may thrive in damp and high-moisture corners of your house. More often, termites attack structural trusses such as roofing posts and beams.

Having your lumber treated may prevent significant damage to your property that results in huge expenses in house repairs and maintenance.

The bottom line is that wherever wood gets in contact with concrete, the lumber should always be pressure-treated.

But why use treated wood indoors? The wood needs to be protected from harmful environmental elements that can cause decay or exposure to termite infestation.

Also, the wood should be treated if it is regularly exposed to moisture or positioned in damp areas such as near a leaking pipe or in the laundry room.

Precautions When Using Pressure Treated Wood

Among wood experts, controversies and debates have surfaced regarding the use of pressure-treated wood in a basement—or any interior application for that matter. 

  •  Chemical Risks - A certain amount of toxic materials is present in treated lumber. These chemicals may not be good for the health of the occupants of the basement. During construction of your basement, workers should wear masks and goggles, as there are chemicals emitted while cutting or sawing the wood.

  • Warping and Shrinkage - Pressure-treated wood tends to deform and crack over time. The wood may get saturated with the preservative treatment. After a few years, shrinkage and warping may be noticed on treated lumber.

  • Uneven and Dull Color - Due to the chemical infused into the wood, it may appear to glow in the hue of green. Moreso, it does not look smooth and glossy. This is the reason why an outer coating is needed to apply to make the wood glossy and appealing if it is used as a decorative material for your home interiors.

  • Not Easy to Recycle - The chemicals present in the wood are anti-corrosion. They are also harmful to livestock, as with humans, too. Special treatment and handling are needed after use or when disposing of the wood, thus increasing cost.

The marriage of wood and concrete, whether you are a construction engineer, architect, or just a DIY enthusiast, gives rise to a few questions listed below. The answers can offer you some useful insight as you plan for your basement improvement and remodeling.

Will Pressure-Treated Wood Rot In Concrete?

The pressure-treated wood will rot in concrete over time. Compared to untreated wood, the rotting process is much slower, but it still eventually rots.

The rotting speeds up when the concrete base is always wet or when there is water pooling that never drains. In this situation, the wood, even pressure-treated, will absorb the water that causes it to rot.

pressure treated wood and concrete used as foundation

How Do You Keep Wood From Rotting On Concrete?

Gravel can avert the rotting and decay of wood on concrete. While the moisture produced in concrete hastens the decay of wood, tamping down gravel can prevent this.

Gravel allows water to drain quickly away, thus making the wood always dry which can stop or slow down the decay process.

Do I need To Use Treated Wood On The Basement Floor?

It is a must to use treated wood for your basement floor. The reason behind this is that your basement flooring comes into contact with and is exposed to the moisture that comes from the concrete floor.

Hence, the preservative treatment present in the wood could ward off the moisture to a significant degree.

Can You Put Pressure-Treated Wood Directly On The Ground?

Yes, you can place pressure-treated wood directly on the ground. This applies to lumber that is stamped as “Ground Contact,” which makes it eligible to be placed directly on the ground.

As the name implies, ground-contact lumber is treated to a higher degree of resistance to rot and decay even where the lumber directly touches the ground.

Piles of pressure treated timber. For sale outside hardware store warehouse.

What Is The Difference Between Brown Treated Lumber And Green Treated Lumber?

Green treated lumber has become a tradename in the industry lingo. It is still the same treated wood, and the green hue is the natural resulting color after the pressure treatment process.

The brown variant gives the traditional brown finish due to the brown dye added to the pressure treatment. The latter, however, is more expensive.

What Happens If You Don't Stain Pressure-Treated Wood?

Staining pressure-treated wood is important. Since pressure-treated wood becomes porous, without staining with paint or sealant, it becomes vulnerable to damage.

Without stain, rainwater and dew can easily seep in and the liquid gets absorbed, causing the wood to swell, then it shrinks when it gets dry. This cycle of swelling and shrinking causes wood splinters, cracks, blemishes, and eventual damage.

unfinished basement framing using pressure treated wood. Should You Use Pressure-Treated Wood In A Basement

In Closing

If you want your basement project to look polished and professionally managed, do not get caught up in the big-picture scope. Pay attention to the smaller details and the rest will follow.

Take adequate time and thoroughly analyze the design and the structural elements. And the use of pressure-treated wood is one important material to consider.

Pressure-treated wood should be used for your basement. With this, you have peace of mind in the long run. You are assured that your wood interiors will not rot, get damaged, nor infested with termites and other wood-boring pests.

In the end, you will be stress-free from worries about soaring maintenance costs for your property.

Remember, the basement can be an extension of your home. Give it your full attention to be one living space for you and the whole family!

Leave a Reply