Lumber Basics
Pressure-Treated Lumber
Lumber infused with chemical preservatives under high pressure to resist rot, decay, and insect damage for outdoor and ground-contact applications.
In-Depth Explanation
Pressure-treated lumber undergoes an industrial process where wood is placed in a sealed cylinder and chemical preservatives are forced deep into the wood fibers. The most common chemicals today are ACQ and copper azole. It is essential for decks, fences, retaining walls, and ground-contact applications. Different retention levels are rated for above-ground and ground-contact use. Always check the end tag before purchasing.
Usage Example
We used pressure-treated 4x4 posts for the fence because they will be set directly into the ground.
Related Terms
wood-preservative
decay-resistance
softwood