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...

Bearing: A structural support, usually a beam or wall, which is designed by the building designer to carry the truss reactions to the foundation. [For all images, See PDF or View in Full Issue.] MiTek’s engineering software uses two common types of bearings, roller and pinned. There is...

The HTTH6.5 heavy tension tie is designed to meet the growing demands of modern construction. This product combines state-of-the-art design with rigorous testing, offering a robust and reliable solution for high-load applications. Its painstaking engineering and precision manufacturing ensure...

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...

This article appears in the May 2024 issue of STRUCTURE Magazine as Part 7 of 9. Reprinted with permission. This multi-part series discusses significant structural changes to the 2024 International Building Code (IBC) by the International Code Council (ICC). This article includes an overview...

At Simpson Strong-Tie, we continually look for ways to improve our offerings for the building industry. During one of our periodic product line reviews, we realized there was a void to be filled in our holdown line for residential construction. Over the last decade, we’ve made strides...

In a recent discussion with several very well-informed industry folks, it became clear to us that interpretation of member-to-member gaps may not be clear. In particular, we need to take a closer look at Chapter 3 Quality Criteria for the Manufacture of Metal-Plate-Connected Wood Trusses of...

This article appears in the April 2024 issue of STRUCTURE Magazine as Part 6 of 9. Reprinted with permission. This multi-part series discusses significant structural changes to the 2024 International Building Code (IBC) by the International Code Council (ICC). This article includes...

The 2024 International Residential Code (IRC) is available. One addition to the new residential code deals with the wood framing around stair openings. This addition was submitted as part of a code change proposal by the Stairbuilders and Manufacturers Association (SMA) based on the work and...

Typically, trusses are spaced evenly. The spacing shown on MiTek engineering drawings is a tributary area carried by the trusses. Each truss is designed to support one-half of the roof/floor load on each side. The spacing between the trusses may be of any combination if the tributary area does...