This paper reports on the results from extensive finite element study of single storey industrial halls subjected to the action of localized fires. The results show offer structural resistance in fire situations that are much higher than would be expected from a prescriptive approach. It has been shown that actual resistance of these structural members in fire situations can exceed their primary resistance mechanism through flexural action only. Alternative load transfer mechanism through catenary action offers the added resistance at much higher temperatures than the conventional critical temperatures from prescriptive design. The paper also presents simplified calculation procedures that can be used to reasonably predict the structural resistance at elevated temperatures considering the catenary action