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A steel frame in a factory is shown in the figure below. The detail of roofing system is shown in the detail A. A corrugated sheets, heat insulating sheets and roof covering were used and supported by purlins spaced at 2 feet. The span of purlin is 20 ft. The floor beams are supported by girders, which in turn are supported by the columns. In addition to the weight of the structure, loads consist of a uniform live load of 100 psf and dead load of 30 psf. The maximum live load deflection must not exceed L/360 of the span length. The thicknesses and density of roof materials are shown in the Table below: Material Thickness, in Density, Ib/ft |Corrugated sheet Heat insulating sheets Roof Covering 2/16 in 0.013 0.15 in 450 50 40 AB (D 15 35 35 Detail -A Detail -A J L Rc Footing Pe Footing fan Roof Covering Heat Insulation Sheets Corrugated Sheets Furlin Main Girder Detail "A" 26 ft a) Determine the loads with exposed to floor beam and grider? b) Get the results of moments using STAADPRO software c) Select suitable lightest section for purlin and girder