Manufactured Metal Building Roof Collapse: What Actually Happened?

This paper will describe a forensic investigation that was performed on a manufactured metal building that suffered a partial roof collapse following a rain storm. The building was a manufacturing plant and the collapse resulted in the plant being offline. Quickly returning the plant to operation was very important to the owners. The owner’s engineers quickly concluded that the roof drains had been obstructed, and the z-shaped roof purlins failed due to overload by ponded water. The owner’s engineers directed the contractor to rebuild the roof to match the existing. And, further investigation by WJE determined that the partial roof collapse was not a result of overload of the roof purlins but rather the result of an instability associated with a beam-over-column connection. This paper will review the failure analysis as well as review beam-over-column connections and their history in the ASIC Specification.