· for dimension lumber wider than 12 (all grades except dense structural 86, dense structural 72, and dense structural 65), tabulated bending, tension and compression parallel to grain design values for 12 wide lumber shall be multiplied by the size fac-tor, cf = 0. 9. · what is dimensional lumber and how does its size system work? It also developed inspection and accreditation programs. · whether in residential framing or commercial infrastructure, understanding dimensional lumber specifications is critical for compliance with building codes, achieving structural integrity, and optimizing load-bearing performance. · a comprehensive chart that shows nominal lumber dimensions and their actual sizes in inches and millimeters. I also explain why they are different. The move to set national standards for lumber in the united states began with publication of the american lumber standard in 1924, which set specifications for lumber dimensions , grade, and moisture content; The grades are based on a visual or digital scan evaluation of each lumber piece. Use these southern pine specification guidelines to help specify the most economical and efficient use of southern pine lumber products and minimize misunderstandings between specifier and supplier. Learn about dimensional lumber and nominal vs. Dimension lumber grading rules limit natural characteristics and manufacturing imperfections that affect the strength and utility of the piece.
