Cold-formed steel (CFS) purlins as the secondary frame are most common in roofing systems due to the high strength-weight ratio and ease of shape forming from the rolling sheets. Typically, the thin-walled CFS purlins have low lateral stiffness and low torsional rigidity susceptible to cross-sectional buckling and member buckling. The roofing sheets attached to the purlin flanges act as an advantage in continuous bracing, subsequently enhancing the buckling loads with coupled deformations and altering the failure modes compared to the nominal purlins. Through-fastened systems (TF systems) are directly attached to the purlin flange, and SSMR systems are made using hidden clips. In SSMR systems, the upper end of clips is connected to the panels, while the lower end is fastened to the purlins. The SSMR systems are also called screwless systems, and this type of system is known for better performance and durability due to the hidden clips. Typically, the deformation of the purlins interacting with roofing systems is characterized by bending in two directions and rotation of the purlins to uniform and non-uniform torsion. In TF systems, sheeting provides adequate shear stiffness in the lateral direction, full lateral restraint is considered, and in-plane bending and torsion are considered in the analysis. Under these assumptions, the codes of practice prescribe approximate methods and reduction factors in determining the nominal strength of the purlins interacting with roofing systems. However, the sheeting in SSMR systems does not ensure adequate shear stiffness due to the connection methodology adopted. Hence, deformation in the lateral direction restricts the applicability of the methods available in the codes of practice. The present code provisions are limited to determining the strength of the purlins interacting with TF systems. Hence further research is needed to study the performance of SSMR systems.