Page no. 37 Research report Long span structures for Stadium roofing Abstract A roof structure with a span of more than twelve meter is called long span structure. Long span structures are widely used in Stadiums, Gymnasiums, Sports halls, Swimming pools, Ice tracks, Skating rinks and Indoor sports. Stadium is a space for outdoor sports, concerts, events and consist of the field or stage that is surrounded by the tiered structure, designed for the spectators to stand or sit and view the event. Due to the function of the tiered structure, it needs to be protected (roofing to be provided) against the weather conditions and to create optimum circumstances for carrying out different activities. The stadium roof needs to provide a Barrierfree and column-free internal space, which is achieved by a lightweight and long span structure. The roof provides users with natural light and ventilation, and provides the best condition for grass growth. The various types and basic systems of long-span structures and their effectiveness are analysed to provide design advice, structural aspects integrated with architectural design, and the forces that affect the structure. Study of retractable roof structures that can host a greater variety of activities, improve the quality of their implementation, and the quality of visitors’ experience. Research and identification of characteristics of retractable roof structures lead to the design of new moving systems that can with the application of the moving principle change the purpose of movable elements or assume the characteristics of other fundamental systems. The attempt to device new methods of construction leading to weight reduction and material development to increase the efficiency is continuously made. Hence several recommendations arrived based on materials, aesthetics, limitations and flexibility for different types of structures can be made use appropriately during the construction of sports facilities. Keywords – long span structures – cable structures, space frames and pneumatic, retractable structures. Introduction Sports is an activity involving physical exertion and skill in which an individual or team competes against another or others. Sports complex is designed to showcase and practice various sports. It accommodates various sports facilities such as tracks, fields, swimming pool, cafeteria, warm-up area, etc. In sports complex most of the structures have large spans due to the provided fields, tracks or courts provided, which results in long span buildings. Stadium creates a landmark on the urban scale. It provides employment on the urban scale for maintaining the complex, repairing and staff. The Stadium is one of the main spaces requiring a long span structure. Stadium is a place for competitions, events, concerts, etc. It requires an unobstructed view and lightweight roofing (structurally). The long span roofing system were used in the later years of 19 th century for stadiums. Built in 1960 and opened in 1965 stadium Houston astrodome was the world's first fully closed, multi - purpose stadium in US. The roof was constructed of rigid steel covered. Where in 1964 Tokyo, a Japanese architect Kenzo Tange designed two smaller venues for swimming arena of 9,000 standing and 4,000 seating spectators. The arena supported a suspension roof that was composed of steel cables draped from a single tall mast on the perimeter of the circular shape. Concrete panels were hung from the cables to form a semi-rigid roof structure that gave the arena a natural look. Advanced for its time, this roof structure was the result of extensive tests, models, and material research. In 1972 Munich, where Germany was chosen for 1972 Olympics a lightweight roof was constructed for the existing stadium in order to create airy feel, which consist of transparent