Supermarket Roof Collapse in Burnaby, British Columbia, Canada

Part of the roof of the newly completed supermarket at the Station Square development in Burnaby, British Columbia, Canada, collapsed during the opening day. Framing was steel bar joists and Gerber system beams, and the roof was used as a parking deck. The government of British Columbia established a commissioner inquiry to ascertain the causes and to make recommendations that could prevent similar occurrences. The principal causes of collapse were an undersized beam and inadequate buckling resistance of both the compression flange of the cantilevered beam and the beam column assembly. The procedures that led to the design error are examined in detail. The inquiry made recommendations designed to strengthen the qualifications of engineers offering consulting services to the public, to clarify the lines of responsibility in the construction industry, and to tighten the practices used in design. Technical recommendations are also made with respect to the design of roof systems of the type involved, which were promptly acted upon by the Canadian Institute of Steel Construction.