The National Lumber Grading Authority (NLGA) is the grading agency having authority over establishing lumber design values for Hem-Fir (North) lumber and conducting on-going testing to verify the design values. The NLGA follows inspection and grading rules approved by the American Lumber...

Specific gravity (G) is a measure of wood density affected by the specific species or species combination of the commercial grade, growth region, and grading rules. It is the single most important lumber property for the strength of mechanical fasteners, such as nails and screws used in...

Sponsored by the Virginia Tech Continuing and Professional Education program, a three-day program on light-frame and mass timber construction design topics will be offered on May 14–16, 2024 in Blacksburg, VA. Joining me as instructors this year are Scott D. Coffman, PE, John Holland, MBA,...

In response to the increasing demand for mass timber construction, Simpson Strong-Tie  has created mass timber solutions for these builds. These product additions include our Heavy Seated Knife Plate (HSKP), ACBH concealed beam hanger,  and CBH concealed beam hanger. Gain insights into...

Originally intended as an improvement in lumber manufacturing, most dimensional lumber used for framing has a radius corner created during the planing process. The rounded corner radius is intended to make the lumber easier to handle and can improve the lumber’s performance because sharp...

The American Wood Council (AWC) released its three new 2024 wood design standards: the National Design Specification® for Wood Construction (NDS®), Wood Frame Construction Manual (WFCM) for One- and Two-Family Dwellings, and Fire Design Specification for Wood Construction (FDS). These...

Lumber has ability to handle higher stresses under shorter periods of time. This characteristic is known as Load Duration Factor. Load Duration Factor typically ranges from 0.9 to 1.6 and is based on the amount of cumulative time the load is applied to the structure. Per the National Design...

Timber Products Inspection has compiled design value comparison tables for several popular species and species groups as a helpful tool for truss manufacturers to determine if a lumber grade and/or lumber species substitution satisfies the original truss design. The data used comes from the 2018...

Once again, Virginia Tech will be offering its popular two-day course on topics related to wood construction. This year’s course, to be held on April 26–27, will focus on practical code-conforming design of wood structures based on provisions of the 2018 National Design...

How does ripping lumber, cutting a board along its length, affect its grade or strength values? Structural lumber is graded or inspected which provides designers, through the National Design Specification® (NDS®) for Wood Construction, the strength/design values for the lumber members....