AbstractThin‐walled sections distortional buckling phenomena is treated in EN1993 part:1‐3 (EC3‐1‐3) through the calculation of reduced thickness of stiffeners group, mainly by the application of the simplified method presented in this specification which comes with a limitation of applicability to non‐standard sections or with multiple stiffeners that can result in over conservative or insecure results.With the objective of facilitating de study/utilization of such kind of sections by designers, maintaining a safe set of results and without the overwhelming amount of calculations, the alternative method in clause 5.5.1(7) is used, applied only to the distortional analysis and correspondent effective thickness of stiffenersThis alternative method allows the use of Linear Buckling Analysis (LBA), which, in this paper, are obtained through the Generalized Beam Theory (GBT) by the GBTUL computer application that applies this theory in the identification of distortional modes and buckling critical loads calculation. The results are then incorporated in EC3‐1‐3 algorithm as defined in clause 5.5.1(7). For the application of this alternative method the LBA results are integrated with EC3‐1‐3 using the Class4Section application, updated for this paper, which uses the critical buckling loads for the calculation of the critical stress of stiffeners group. This more generic approach by the alternative method is easily implemented in computational environment.Following previous work by the authors, the section moment capacity is analyzed in this paper by applying this alternative method and comparing it with available experimental results for selected thin‐walled sections mainly used in flexural problems, namely Sigma and Omega section types, as well as the most commonly known C and Z sections, but with multiple stiffeners.