Wind load resistance of modified bituminous roofing systems

Wind effects on roofing systems are dynamic, because of wind's fluctuation in time and space. Therefore a dynamic means of evaluating roofing systems is beneficial for identifying the component in a roofing system that has the weakest resistance against wind uplift forces. The Special Interest Group for Dynamic Evaluation of Roofing Systems (SIGDERS) commissioned a unique North American roofing facility, which has been used to evaluate a mechanically fastened modified bituminous membrane roof system under three different test methods: the Factory Mutual FM-4470 static test standard, the UEAtc (European Union of Agreement) procedure, and the SIGDERS-developed dynamic load cycle. Comparison of the results of these tests shows that UEAtc and SIGDERS tests produce failure modes similar to those observed in the field. The SIGDERS load cycle was completed in much less time than the UEAtc procedure.