15mx4 multi span light steel roof including the design details of steel structure canopy, including: 4-span steel structure roof, 15m per span, 7.2m column spacing. Large steel structure canopy is included. The roof is equipped with fans, suspended air ducts, suspended ceilings, etc. 15mx4 continuous span light steel roof including steel structure canopy design details, including column base anchor bolt plan, steel roof structure plan, roof purlin