Bottom Chord Live Load Concurrency and Truss Design
Research Report No.: 1607-02
Issue Date: August 16, 2016
Update Date: August 16, 2016
Correct loading is key to proper truss design and results in safer trusses, better truss performance and ultimately lower costs. However, there currently is a discrepancy regarding concurrency of bottom chord live loads between ASCE 7, the IBC and the IRC. This report examines the discrepancy and the correct loading for proper truss design.
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.