AC2® pressure treated lumber uses southern yellow pine to provide optimum strength and appearance on any outdoor project left exposed to the elements. Treated lumber is a renewable building product that's safe for use in any application, including those around pets, playsets, and vegetable gardens. AC2® treated lumber can be painted or stained to match any existing project. Wood is a natural product with many unique characteristics and properties. While wood's strength and workability make it highly suited for general construction and building projects, other inherent characteristics make it subject to checks or splits and warping or twisting. In addition, the actual size is almost always smaller than the nominal (common name) size and may vary slightly depending on the moisture content.