Performance of roof fasteners under simulated loading conditions

Conventionally, in North America, design loads for roof attachment systems are determined through static testing. While presenting the development of a dynamic setup, this paper compares the fastener pull-out loads under static and dynamic conditions. This has been systematically performed for steel and wooden decks under various fastening parameters. Experimental data have indicated that the fastener failure load and mode differ significantly under dynamic testing in comparison to static testing. With steel decks, the fastener pull-out resistance decreased by 30-50% under dynamic conditions, whereas results with wooden decks, the resistance decreased by 10-30%. Therefore, for the design of mechanically attached roofing systems, one should use for the fasteners the allowable design load derived from dynamic testing. Preliminary investigations have also been carried out and further research efforts are in progress on the fastener service life predictions.