What is pressure treated lumber?

Pressure treated (PT) lumber is wood that has been infused with chemical preservatives to protect the wood from rot and insects. The wood is placed in a depressurized holding tank that removes the air and replaces it with a preservative. This process is the best way to avoid harmful rot and insects but does not prevent weathering and corrosion.

When working with treated lumber, we suggest you wear gloves, eye protection and a dust mask (NIOSH N95) when handling wood. Due to preservatives in pressure treated wood, it should never be burned. Sawdust and scraps should be disposed of in a landfill.

Keep your outdoor structures beautiful for years by building with pressure treated lumber.

In addition to the preservative treatment that enables wood to last a long time, it has all the environmental and other advantages usually associated with the wood itself. Its source is a renewable and quickly replenished resource grown on managed timberlands, requiring less energy to produce than alternative building materials.

There are many types of treated lumber.

Treated wood has outstanding environmental qualities with regard to sustainability, carbon footprint, and low-energy production as confirmed in its life-cycle assessment. There are three main families of treated lumber used in construction: Borate, Alkaline Copper Quat (ACQ) and other rot-resistant treatments, and non-combustible (Non-Com). See the complete list under Additional Information.

Can you paint pressure treated lumber?

Pressure treated (PT) lumber takes months to shrink and re-contract on and off so the paint will crack and not adhere correctly. Painting pressure-treated wood comes with complications caused by the very same treatment that allows the material to last outdoors. To produce pressure-treated wood, the milled lumber (typically pine or cedar) is saturated with chemical preservatives. These chemicals minimize the wood’s natural vulnerability to insects and rot, but it also leaves the wood rather wet – a state that will lead to your coat of paint eventually peeling. With that said, it can be done but is quite a process to paint treated lumber, so why would you?

Where can I use pressure-treated lumber?

Wood for any outdoor project should be pressure-treated, while wood for indoor projects should not be pressure treated. The chemicals used to pressure treat wood aren’t safe for humans, this is why non-pressure treated wood is still required for use indoors, and why builders recommended that you only use pressure treated lumber for your outdoor projects like decks, pergolas, etc.

Is treated wood as strong as regular wood?

Pressure treated lumber is no stronger than untreated lumber. The difference between the two is that pressure treated lumber will resist the elements better than untreated due to chemical preservatives added, and so will maintain its integrity in conditions that would cause normal wood to rot.

Pressure treated lumber prices.

You’ll find value and selection on treated lumber and much more at Front Range Lumber. Lumber is a commodity with prices fluctuating due to market conditions. We stock a large selection of different types of treated lumber in a wide range of sizes at very competitive prices for the top quality we sell.

Pressure treated lumber grades.

Most treated lumber does not come in different grades, the exception being plywood, which will come in both ACX and CDX grades. Virtually all treated lumber is considered for construction only – those grades do not take appearance into consideration. In most cases (except deck framing), the treated wood used will be covered by trim, drywall, paint, etc. Front Range Lumber does have some of its own wood treated, translating into a better quality than widely available. Based on appearance and shrinkage issues, Front Range Lumber does not recommend the use of treated lumber for decking boards (use for framing only).

Weyerhaeuser Treater Series™ Lumber – treated lumber that starts straight and stays straight.

Weyerhaeuser’s Treater Series lumber is graded by a patented, computerized system to ensure that every piece starts straight and stays straight.  For more information go to our Treated Lumber page.

More information on treated lumber.

Read our Additional Information section for important information on treatment processes, use/retention charts, size chart, grades, and health and safety concerns when working with treated lumber products.

Treated Lumber Resources:

APA – The Engineered Wood Association: www.apawood.org
Western Wood Preservers Institute: www.wwpinstitute.org