ABSTRACTThe sleeve joint is a bolted connection frequently employed in the purlins assembly of secondary structure in industrial building, because it facilitates the assembly of the structure. The joint behaviour determines the purlin structural behaviour.Recently, authors have proposed a simple approach to predict the stiffness and strength of the sleeve connection, depending on the lap length to depth ratio [1]. It includes rotational springs on the joint bolt lines, actuating in a coordinated way.In the present paper, multi‐span purlin models including the semi‐rigid nature of the joints are developed. They consist on beam and rotational spring finite elements, based on the previous approach. The joint behaviour influences the stresses and deformations developed by the purlin, which can be analysed, allowing for safety design in elastic range.The multi‐span purlin design with sleeve joints are studied, employing a model that includes the realistic behaviour of joints. The objective is to address the minimum lap length to depth ratio of the sleeve joints, needed for a confidence purlin design. This work is proposed in the framework of the optimized multi‐span purlin design with cold formed profiles, according to the European standards.