The Heavy End Bay System is the most recent purlin sytem to be made available from Hi-Span. A minimum of five equal bays is required for the system to perform economically with the use of heavier end bay sections. Sleeves are required at every purlin/rafter connection, no double span purlins. The system offers a very economical solution to the user in the long span multi-bay buildings, because considerable savings can be made in using lighter inner bay purlins, with the added advantage of simple erection procedure.