TABLE OF CONTENTS The numerous species of wood can be divided into two basic classifications: softwood and hardwood. These classifications do not necessarily refer to the hardness or softness of the species, but rather to the type of tree from which the wood is taken.
Hardwood comes from trees that shed their leaves at the end of a growing season (such as oak, hickory, chestnut, elm, maple, and birch). Softwoods, on the other hand, are trees, such as evergreens, that do not shed their leaves (cedar, pine, hemlock, larch, and spruce, for example). Hardwoods are generally used for flooring, furniture, cabinetry, and millwork. Softwoods find wide application as framing members, although some species of pine are used as shelving or are incorporated into various types of millwork.
The characteristics of wood vary from tree to tree as well as from section to section within a tree. Therefore, some method is required to select and grade pieces of lumber cut from a tree to form some degree of uniformity Then organizations were established to set the standards for various grades of lumber. They have the authority to inspect member mills to ensure that the buyer receives the quality they bargain for.
The Western Wood Products Association (WWPA) was formed around 1900. By 1924, various other grading associations in the United States developed product standards with the assistance of the U.S. Department of...
