How Long Does Pressure-Treated Wood Last? It depends on the climate, the type of wood, its uses, and how well it's maintained. While pressure treated poles can stay up to 40 years without any signs of rot or decay, decks and flooring might only last around 10 years.
While a treated 4x4 may last 10 to 25 years, depending on the wood, the soil, and weather conditions, following the simple steps below could double or triple that number. By comparison, an untreated wood fence post may need replacing in as little as five years.
Pressure treatment helps protect wood from rot and insects with the help of high pressure and preservatives, helping to extend its life. Generally, pressure-treated wood can last anywhere from 10 to 40 years, depending on a few factors.
Seal or Stain the Wood
Staining or painting pressure-treated wood with a high-quality stain or sealant helps to repel water and prevent the wood from cracking or splitting. This not only contributes to prolonging the life of the wood but also enhances its appearance.
Although treated wood is protected against decay and termite attack, the application of a water-repellent sealer to all exposed wood surfaces is recommended upon completion of construction. This sealer will help control surface checking (splitting or cracking) and provide an attractive appearance.
Pressure-treated wood contains preservatives to prevent rot and insect damage, but it remains vulnerable to the sun, wind, moisture and dirt. Learning how to stain pressure-treated wood can extend the life and improve its appearance.
Yes. Although pressure-treated lumber is pre-treated with chemicals, preventing insect damage, it is NOT waterproofed. In fact, the chemical treatment actually causes the lumber to dry out quicker and absorb more water than untreated lumber.
Because this type of decking is treated with chemicals for protection, it can be hazardous when not handled correctly. If the wood is burned, trimmed, or cut, it can release harmful toxins into the air. Pressure-treated wood should not be used for gardens or come in frequent contact with food and water.
Do not use treated wood for cutting boards or countertops. Only treated wood that is visibly clean and free of surface residue should be used for patios, decks and walkways.
Termites will eat pressure treated wood if the wood is old enough that it has lost some of its protection, if they can find an untreated edge, fi the wood stays damp enough for long enough and starts to rot, or if there is no other wood available.
Pressure-treated wood is as susceptible to damage from the sun, rain, and other outdoor elements as non-treated wood. But you can prevent that from happening. Staining pressure-treated lumber prevents cracks and splits caused by seasonal changes, prolongs its life, and preserves its natural beauty.
While pressure-treated lumber is technically wood, you should not burn it, as its preservation chemicals include copper, which is a heavy metal.
Rot is a Real Threat for Any Wood
Pressure-treating can make wood water-resistant, but it's not 100 percent rot-resistant. Any time the wood moves, bends, or cracks, water can enter.
The bad stuff seeps downward right into the “Hot Zone”. Mix in some oxygen, the moisture from below, the fact that concrete holds a constant temperature and moisture, and those wood posts are going to prematurely rot. No exceptions.
Ground-contact pressure-treated lumber can be used either above ground or in contact with the ground. Has twice the level of chemical retention and protection compared to above-ground treated wood. Must be used when lumber is less than 6 inches from the ground or has poor ventilation.
Once installed, pressure treated lumber can last for many years submerged in water, and unlike steel it is not vulnerable to corrosion or electrochemical reactions, and it can last as long or longer than naturally moisture-resistant wood species.
However, the zinc in galvanized nails reacts chemically with cedar and redwood. Nail manufacturers recommend that you go with aluminum or stainless steel fasteners when you're using either of these woods—and whenever you're using pressure-treated wood. (The preservatives incorporate salts that react with the zinc.)
When it comes to comparing treated wood vs. cedar, pressure-treated wood is the sturdier and more weather-proof of the two. It's highly resistant to insect attack and rot, and special versions rated for “ground contact” can be buried in soil and will continue to shrug off decay for decades.
It's because the chemicals used to pressure treat wood aren't safe for humans. You can find arsenic in all older pressure treated lumber and some new materials, while copper is widely used in even the newest pressure treatment formulas.
Well, until about 2003, the chemical used to pressure treat wood was chromated copper arsenate (CCA), which, as the name suggests, contains arsenic. Arsenic is a poisonous compound, and there is a risk that over time, it may leak out of the wood, and could come into contact with someone walking barefoot on a deck.
While selecting brown timber may be more desired due to its traditional appearance, it's worth noting that the dye is added as an industrial preservation process rather than a decorative finish as eventually all treated timber will fade in colour over time (this can be prevented by regular maintenance).
It is not recommended where decks are subject to significant sun exposure. It also must be reapplied more often than most stains, typically every 2 to 3 years, depending on sun exposure. 1 Semi-transparent stain adds some color to the wood and offers a moderate amount of UV protection.
Maintaining Your Sealed Deck
Maintaining your wooden deck is the best way to keep it looking it's best for as long as possible. Cleaning your deck, keeping it algae-free, and applying a fresh coat of sealant once every year will help keep the wood from weathering and cracking.