Lumber designated for 'Ground Contact' can be placed directly on or in the ground. Lumber that's stamped 'Above Ground Use' should be used only where it won't touch the ground, such as deck railings or fence boards. The level of rot resistance is directly related to the amount of chemical preservatives in the wood, and the type of chemicals used. However, it's important to note that not all treated wood is created equal.
The result is an exterior-grade wood that's ideal for building decks, fences, sheds, picnic tables, swing sets, and other outdoor projects. The boards are rolled into giant pressurized tanks where chemical preservatives are forced deep into the wood's fibers. To start, pressure-treated wood is softwood lumber, typically southern yellow pine, that's been chemically treated to resist rot, decay and termites.
Pressure-treated wood has been around for nearly 70 years, yet most of us still know very little about this popular outdoor building material.
