When installing SCHRAG purlins, we basically distinguish between two different systems. So-called single-span girder systems are particularly economical solutions that are predestined for buildings with few girders and low loads. The single-span purlins can be installed either suspended above the girders using purlin shoes or between the girders.
Coupling purlins for large spans and high loads
Purlins with lower material thicknesses reduce the weight
Coupling purlin systems of unlimited length
Coupling purlins are installed alternately in bays with a wide or narrow flange at the top. This ensures a rigid connection between the purlins and the beams. Theoretically, such continuous beams can be of unlimited length. In order to keep the weight of the entire system as low as possible without affecting the statics, smaller material thicknesses are used in the inner spans compared to the end spans. If necessary, the continuous beam effect of the coupling purlins for the main supporting structure must be taken into account and consultation with the planner of the supporting structure must be held.
