Materials

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. 

I am a building inspector and I have a question on information provided on truss design drawings. What does the uplift reaction number represent? Some manufacturers are very specific and state “to provide for mechanical connection of the truss to the top plate with a connector capable of withstanding a specific load.” Others simply list the uplift reaction with no further information. These are the ones that have caused a debate as to what the number actually represents.

We are planning to add 1/2 in. cement board and 3/8 in. quarry tile to a kitchen floor. We need to know if the floor trusses will handle the additional weight. The floor trusses are 19.2 in. O.C. and the loading numbers are 40-10-0-5. What do these numbers mean?