Pressure-treated wood is wood that has been cured using pressure to increase its durability and resistance to rot, insect infestation, mold, and water damage. So how long does pressure-treated wood last?
While pressure-treated wood can last for at least forty years without showing indications of rot or decay, decking and flooring may only last about ten years. However, the chemicals used in the pressure treatment, the type of project, the wear, and tear on the wood, the type of wood, the amount of exposure to adverse wet environments, and how well it is maintained all have an impact on how long it will last.
Below, we’ll go through each of these features and how they affect the longevity of pressure-treated wood.
How Long Does Pressure Treated Wood Last? The Facts
Factors affecting pressure-treated wood’s longevity
How Climate Affects Pressure-Treated Wood
The type of climate in the area you are in might influence how long your pressure-treated wood will last. This will be mainly influenced by where you plan to use the wood.
The wood will stay in ground contact longer in high humidity, sub-tropical, or tropical areas. Wood made for ground contact is mainly used on the ground or in contact with the land, soils, vegetation, or debris.
In addition, the wood is also best for freshwater applications or where there is exposure to daily moisture. Wood made for ground contact has twice the ability to hold chemicals as one made for above-ground use.
2. Type of wood.
Some wood species retain more chemicals than others, allowing them to endure longer when appropriately utilized.
The species are:
- Pine/Cedar: The Southern pine is one of the most popularly used types of wood in framing in the eastern United States. It has sturdy logs and high sapwood content, which is good at absorbing preservatives.
- Red pine and Ponderosa pine are used in the northern United States and Canada.
- Douglas fir is popular in the western United States and Canada.
- Hem-Fir This western species is more feeble and inclined to warping and splitting than the Douglas Fir, but very responsive to preservation.
3. Chemicals used
Preservative chemicals are infused into the wood under pressure in a vacuum-sealed tank, retort, or steel cylinder during the pressure treatment process.
The amount and type of chemicals used in this process will affect how long the wood will endure. For example;
- Chromated Copper Arsenate (CCA) is used in heavy applications like shakes and shingles, utility poles, and wood foundations. In this type of treated wood, the functions of copper and arsenate act as insecticides, and chromium protects the wood from UV rays. Also, treating wood with CCA makes it challenging to remove the chemical from the wood, hence making the wood more durable.
- On the other hand, wood made for lighter-duty projects is treated with Amine Copper Quat (ACQ), Copper Azole (CA), and Ammoniacal Copper Zinc Arsenate (ACZA), each having a limited range of applications.
Many other chemical preservatives are available, such as Creosote, Pentachlorophenol, Acid Copper Chromate (ACC), Borates, Copper Naphthenate, Copper-HDO, and Polymeric betaine.
Also, you must use the proper hardware and fasteners for the type of pressure-treated wood used. The chemicals will corrode the metal if it is not designed to handle the chemical treatments. Therefore, the corrosion will impair the project’s integrity, thus reducing the life of the wood.
4. use/project type.
What you plan to do with the wood will decide the type of pressure treatment it receives, which will affect how long it lasts.
Various projects subject the wood to different degrees of stress. Those pressures, in turn, require varying amounts of preservatives to provide the best possible protection for the wood.
The amount of preservative required is known as the “retention level.” This is the amount of preservative retained in the wood after treatment. Each preservative has its own retention level for these projects.
Moreover, each wood is labeled with a tag showing its correct use. These appropriate applications range from the lightest treatment (UC1), best only for interior dry conditions, to the heaviest treatment of UC5C, best for saltwater marine conditions.
Proper care and maintenance will extend the life of the wood. Apply a water repellent to decks six weeks after construction is completed and then every year.
In addition, check to see if any fasteners, bolts, nails, or screws are loose due to wood failure or corrosion and replace or fix them. Replace any rotten wood to keep the decomposition from spreading to the wood that comes into contact with it. Also, when needed, apply and reapply the weather-resistant stain.
How do you make treated wood last longer?
For enhanced durability, make sure you apply water-repellent sealers every year and use a mildew cleaning as soon as you see any mildew developing on your wood.
Pressure-treated wood is an investment that is worthwhile, particularly for people who own permanent houses because of how long it lasts. Pressure treatment of wood reassures the user of an extended life of the wood.
Pressure-treated wood can also be painted or stained in addition. Painting and staining are two maintenance procedures that extend their lifespan. You must re-stain or repaint because both staining and painting enhance the appearance of the wood’s surface.
The best stains for pressure-treated wood include
The Pressure Treatment Process
A vacuum is used to remove air from the cylinder and the cellular structure of the wood.
The cylinder is then filled with treatment chemicals under pressure. The treatment chemicals exert 160 pounds of pressure on the cell framework of the wood.
After the pressure treatment, the wood is placed on a drip pad to cure and dry before being shipped to a supplier. The amount of time it takes for pressure-treated wood to dry is determined by the climate and the amount of sunlight available.
Does pressure-treated wood rot?
Every wood can rot, and so does pressure treatment. Fungi mainly cause rot. Fungi are usually microscopic, and they can penetrate the wood and eat the grains of the wood, which causes the wood to decay and later rot. In most cases, wet wood is the most affected by fungi, and therefore, keeping your wood dry would help avoid wood rot.
How do you keep pressure-treated wood from rotting?
Although pressure-treated wood is best known for protecting against wood rot, moisture, and insect damage, it is also vulnerable to damage if not well maintained. When wood bends or cracks, water can enter, which causes the wood to rot. To prevent treated wood from rooting, you can apply paint, sealant, or stain. Wood rot is effectively prevented by using a sealant. It provides effective resistance to moisture, which leads to wood rot. However, these products do not guarantee lifetime protection, but they will provide more extended protection.
Does pressure-treated wood need to be sealed?
Although the chemicals in pressure-treated wood keep the wood from rotting and insects, they don’t keep moisture from getting in. Water can penetrate through the boards of a deck that will be directly exposed to rain, causing it to expand. They will shrink as they dry in the sun. Your deck will become cracked, splintered, and twisted due to this ongoing cycle of swelling and shrinking.
This can be avoided by adequately sealing and maintaining your pressure-treated deck. A sealer can also give UV protection, which will slow the fading of your deck’s color.
While the pressure treatment process offers some protection, sealing your pressure-treated wood will help it look better and last longer.
In conclusion, pressure-treated wood has a lifespan of around 40 years, however, various factors may influence longevity along the way. The company delivers wet pressure-treated wood. As a result, before painting or staining it, you should let it dry.
Furthermore, by using pressure-treated wood, you can add new features at any time. Replace any deteriorated components and paint or stain them to match the rest of the house.