Page 361 - Forensic Structural Engineering Handbook

10.48 CAUSES OF FAILURES

Case History 10: Wood Truss Erection
Dozens of 42-ft-span wood trusses collapsed during construction of a major addition to a
church in British Columbia, Canada. One worker fell with a truss and was slightly injured.
The trusses were approximately 5 ft deep with sloping parallel chords peaking at midspan,
spanning north-south 42 ft between two 22-ft-high load-bearing stud walls of 2-by-6-studs
at 8 in on center. The causes of the collapse appeared to have been inadequate temporary
bracing of the trusses and the incomplete construction of the load-bearing stud wall on the

(a)

(b)
FIGURE 10.10 Wood trusses. (a) Wood roof toppled over during construction. (From
Jozef Jakubowski, Workers’ Compensation Board of British Columbia, Vancouver, BC,
Canada.) (b) Close-up view of collapsed wood trusses. (From Jozef Jakubowski, Workers’
Compensation Board of British Columbia, Vancouver, BC, Canada.)