Long span light roof systems of industrial buildings are frequently designed with cold-formed steel members, leading to competitive solution which allows liberating useful internal space inside the building. This type of structural solution is usually cost saving if it is combined with standardization of the manufacturing process thus enabling specialized solution. This is the case of a family of trussed girders ranging from 0.6 to 1.8 m depth, developed by the steel structures manufacturer and addressed to a standard system for general application enabling to bridge up to 40 m span of light roof construction. Typical buckling behavior of the cold-formed members, with special emphasis to the unsymmetrical stiffened Z section chord members was investigated as well as the effect of the eccentricities in the joints. Numerical and experimental results allowed understanding the buckling behavior of these members as well as confirming its strength capacity. For this both axially compressed tests of the Z chord member and load test of a complete trussed beam were performed and the obtained results were applied to improve the structural design. The comparison between experimental results and those from the prescriptions of the Brazilian design code addressed to steel cold-formed structural members (direct strength method-based strength check) will be presented and commented. The obtained results allowed confirming the actual behavior and ultimate loading condition of the trussed girder
