Materials

When evaluating today’s North American softwood lumber markets, it’s important to keep the relatively recent shift (since 2015) in the controlling ownership of U.S. mills, particularly in the southern yellow pine region.

While steel consumers will likely continue to take a “wait and see” attitude, the findings the DOC emphasized in their report to the president indicate there may be future trade action to protect domestic producers.  President Trump has until April 11 to act on the DOC’s recommendations.

This presentation seeks to explain how to correctly apply live loads to the bottom chord of trusses for uninhabitable attics in accordance with IRC Table R301.5 and IBC Table 1607.1 and ASCE 7-10 Table 4-1.

This report focuses on building code requirements for using fire retardant treated wood (FRTW) in floor/ceiling and roof/ceiling assemblies in Type III building construction. 

The BC beetle kill means changes are on the horizon for lumber harvesting, processing and pricing. 

Quality marks are not substitutes for grade marks—FRTW will include both!

Lumber Design Values

No matter the species, component manufacturers (CMs) purchase and rely on the accuracy and reliability of many different lumber design properties, including: bending (Fb); shear parallel to grain (Fv), compression perpendicular to grain (Fc^), compression parallel to grain (Fc), tension parallel to grain (Ft), and modulus of elasticity (E and Emin).

Quality marks are not substitutes for grade marks—PTW will include both!

Metal plate connected wood trusses are sometimes used in applications or environments that require the trusses to be designed and constructed with chemically treated lumber. The two most common types of chemically treated wood used in trusses are preservative treated wood (PTW) and fire retardant treated wood (FRTW).

This presentation provides an overview of fire-rated assemblies that include wood trusses. Topics covered include assembly testing, Harmathy’s rules, and an examination of fire performance in the field. 

What are the requirements for installing valley sets over roof trusses? I am interested in nailing and support conditions. Some engineers ask for the bottom chord of the valley truss to be ripped to match the roof pitch of the underlying trusses. Is this necessary? How can I calculate values for uplift resistance for the building inspector?