2001 ASD Supplements - unprotected PDF - American Wood Council

L-4 INTRODUCTION TO STRUCTURAL LUMBER2.1 Product InformationStructural lumber products are well-known throughoutthe construction industry. The economic advantagesof lumber often dictate its choice as a preferred buildingmaterial.Lumber is available in a wide range of species, grades,sizes, and moisture contents. Structural lumber productsare typically specified by either the stress level required,or by the species, grade, and size required.This Supplement provides information for designingstructural lumber products in accordance with the NationalDesign Specification (NDS) for Wood Construction.2.2 Common UsesStructural lumber and timbers have been a primaryconstruction material throughout the world for many centuries.They are the most widely used framing materialfor housing in North America.In addition to use in housing, structural lumber findsbroad use in commercial and industrial construction. Itshigh strength, universal availability, and cost saving attributesmake it a viable option in most low- and mid-riseconstruction projects.Structural lumber is used as beams, columns, headers,joists, rafters, studs and plates in conventional construction.In addition to its use in lumber form, structurallumber is used to manufacture glued-laminated beams,trusses, and wood I-joists.2.3 AvailabilityStructural lumber is a widely available constructionmaterial in the U.S. However, to efficiently specify structurallumber for individual construction projects, the specifiershould be aware of the species, grades, and sizesavailable locally. The best source of this information isyour local lumber supplier.AMERICAN WOOD COUNCIL