Pressure treated refers to a process of treating wood to make it resistant to decay, insects, and other forms of damage. The process involves placing the wood into a pressure chamber where it is treated with a solution of water and preservatives, such as copper or zinc. The pressure forces the solution deep into the wood fibers, which makes it more resistant to rot, decay, and insects.
Pressure-treated wood is commonly used for outdoor structures such as decks, fences, and retaining walls. It is also used for building boats, utility poles, and other applications where exposure to moisture and insects is likely. However, it’s important to note that pressure-treated wood can be harmful if it’s not handled and disposed of properly. It’s important to follow the manufacturer’s guidelines and wear protective gear when cutting or sanding pressure-treated wood.
types of pressure-treated wood
There are several types of pressure-treated wood available, each with its own specific use and treatment process. The most common types of pressure-treated wood are:
- Southern Yellow Pine: This is the most commonly used wood for pressure treatment in the US. It is strong, durable, and resistant to decay and insects.
- Cedar: This wood is naturally resistant to decay and insects, but it can also be pressure treated to increase its durability even further.
- Redwood: This wood is also naturally resistant to decay and insects, but it can be expensive compared to other types of wood.
- Douglas Fir: This wood is known for its strength and resistance to rot, making it a good choice for outdoor projects.
- Hemlock: This wood is known for its strength and durability, but it is not as resistant to decay and insects as other types of wood.
It’s important to choose the right type of pressure-treated wood for your specific project to ensure that it will last as long as possible. Your local hardware store or lumberyard can help you choose the right type of wood for your needs.
What is the best type of pressure-treated lumber?
The best type of pressure-treated lumber depends on the specific application and the conditions it will be exposed to. Here are some general guidelines to help you choose the best type of pressure-treated lumber for your project:
For outdoor projects that will be in contact with soil or water, such as retaining walls, garden beds, or dock pilings, use pressure-treated lumber that is rated for ground contact. This type of lumber has a higher level of preservatives and is designed to resist decay and insect damage in wet environments.
For decks and other above-ground outdoor structures, use pressure-treated lumber that is rated for above-ground use. This type of lumber is treated with a lower level of preservatives and is designed to resist decay and insect damage in dry environments.
Consider the species of wood. Southern Yellow Pine is the most commonly used species for pressure treatment in the US and is a good all-around choice for many outdoor applications. Cedar and Redwood are naturally resistant to decay and insects, making them a good choice for outdoor projects that will be exposed to moisture. Douglas Fir and Hemlock are also strong and durable, but may not be as resistant to decay and insects as other types of wood.
Make sure to use pressure-treated lumber that is labeled and certified by a reputable agency, such as the American Wood Protection Association (AWPA). This will ensure that the lumber has been properly treated and is safe for use in your project.
Overall, the best type of pressure-treated lumber will depend on your specific needs and the conditions it will be exposed to. Consult with a professional or your local hardware store to help you choose the best type of lumber for your project.
What type of wood is pressure treated for decks?
The type of wood that is commonly pressure treated for decks is Southern Yellow Pine. This is because it is readily available and has a natural resistance to decay and insects, making it a good candidate for pressure treatment.
Southern Yellow Pine is also strong, durable, and affordable, which makes it a popular choice for deck construction. It can be pressure treated to resist decay, insects, and moisture, which helps extend the life of the deck.
Other types of wood can also be used for deck construction, such as cedar and redwood, which are naturally resistant to decay and insects. However, these woods are generally more expensive than Southern Yellow Pine, and they may not be as readily available in some areas.
Ultimately, the type of wood that is used for a deck will depend on factors such as budget, availability, and personal preference. It’s important to choose a wood that is properly pressure treated and labeled for above-ground use to ensure the longevity of the deck.
How is pressure treatment done?
Pressure treatment is done by placing wood in a large cylindrical tank that is sealed and then filling it with a solution of water and preservatives, such as copper or zinc. The tank is then pressurized to force the solution deep into the wood fibers.
The amount of pressure and the duration of the treatment depend on the type of wood, the preservatives used, and the intended use of the wood. The pressure and duration of the treatment are carefully controlled to ensure that the preservatives penetrate the wood evenly and thoroughly.
Once the pressure treatment is complete, the wood is removed from the tank and allowed to dry. The drying process helps to stabilize the wood and ensure that the preservatives are locked in place.
The resulting pressure-treated wood is strong, durable, and resistant to decay, insects, and moisture. It can be used for a wide range of outdoor applications, including decks, fences, and retaining walls.
It’s important to note that pressure-treated wood should be handled and disposed of properly. Wear gloves, a dust mask, and eye protection when cutting or sanding pressure-treated wood, and avoid burning it as the smoke can be harmful. Additionally, pressure-treated wood should not be used for any application where it will come into contact with food or drinking water.
What is the difference between pressure treated and ground contact?
The main difference between pressure-treated wood and ground contact treated wood is the level of preservative treatment and the intended use of the wood.
Pressure-treated wood is a general term used to describe wood that has been treated with preservatives to resist decay, insects, and moisture. This type of wood is typically used for above-ground applications, such as decking, fences, and outdoor furniture. The treatment process involves placing the wood in a large cylindrical tank and filling it with a solution of water and preservatives. The tank is then pressurized to force the solution deep into the wood fibers.
Ground contact treated wood, on the other hand, is specifically designed for use in direct contact with soil or water. This type of wood is treated with a higher level of preservatives to resist decay and insect damage in wet environments. Ground contact treated wood is typically used for applications such as retaining walls, fence posts, and deck support posts.
So, while both pressure-treated and ground contact treated wood are treated with preservatives, ground contact treated wood is designed to resist decay and insect damage in more extreme environments, such as direct contact with soil or water.
What chemical is used in pressure treated wood?
The most commonly used chemical in pressure treated wood is chromated copper arsenate (CCA), which is a combination of chromium, copper, and arsenic. CCA is used to protect the wood from rot, decay, and insect damage. However, due to concerns about the potential health risks associated with exposure to arsenic, the use of CCA in pressure treated wood has been significantly reduced in recent years, and alternative treatments such as alkaline copper quat (ACQ) and copper azole (CA) are now more commonly used.
Pressure treated plywood
Pressure treated plywood is a type of plywood that has been chemically treated to resist decay, rot, and insect damage. The treatment process involves placing the plywood in a pressure chamber and forcing a preservative solution into the wood fibers. The most common preservatives used in pressure treated plywood are copper-based, such as chromated copper arsenate (CCA), alkaline copper quat (ACQ), and copper azole (CA).
These preservatives help to protect the plywood from environmental factors that can cause deterioration over time, making it suitable for use in outdoor and moisture-prone applications, such as decking, fencing, and exterior sheathing. It is important to note that pressure treated plywood should be handled with care, as the preservatives used in the treatment process can be harmful if ingested or inhaled, and appropriate safety precautions should be taken when working with it.
