The main framing basically includes the rigid steel frames of the building. The PESB rigid frame comprises tapered columns and tapered rafters. Flanges shall be connected to webs by means of a continuous fillet weld on one side.
The main purpose of the columns is to transfer the vertical loads to the foundations. In pre-engineered buildings, columns are made up of I sections which are most economical than others. The width and breadth will go on increasing from bottom to top of the column.
A rafter is one of a series of sloped structural members (beams) that extend from the ridge or hip to the wall-plate, downslope perimeter or eave, and that are designed to support the roof deck and its associated loads.