Steel roofing disaster and the effect of the failure of butt joints

•The causes of a disaster of a roof structure made of welded girders are presented.•The girder elements were assembled with bolted butt joints.•The disaster occurred at night, after several heavy snowfalls.•The roof collapse was a result of the flawed design and mistakes during assemblage.•A concept for the reconstruction of the damaged building is presented.

This article scrutinises the causes of a disaster of a pitched roof construction made of welded plate girders. The girder construction elements were assembled with bolted butt joints. The roofing was made of a folded sheet supported by steel purlins that transferred the load onto welded plate girders. The purlins had no roof bracings. In the analysed case, several days of abundant snowfall preceded the failure that caused a collapse of the roof of a production hall. The investigations that followed confirmed that the collapse started with the cracking of the bolts used to centrally join the roof girders. In the course of the analyses and calculations, it was established that the main cause of the disaster lay in a faulty design of the butt joints between the segments of the steel plate girders. Another factor having impact on the failure was the numerous mistakes in the design and fitting of the steel purlins. The excessive snowfalls were not the main cause of the disaster but were only an additional one. The article also provides a concept for the reconstruction of the damaged building and provides additional details concerning the refurbishment phase.