Abstract This paper presents a validated finite element approach for investigating the behaviour of demountable shear connections in composite floor systems, developed within the LWT‐FLOOR project at the Faculty of Civil Engineering in Zagreb. The project addresses the challenges of sustainability and usability in construction, focusing on improving the life cycle of structural elements through dismantling. The LWT‐FLOOR system, featuring cold‐formed steel (CFS) sections and concrete slabs, was analysed using finite element models validated against experimental data. Two configurations were analysed: The BB series with back‐to‐back CFS sections and the BCWB series with a corrugated web between C sections. Validated finite element models evaluated the shear resistance, ductility, failure modes and initial stiffness of bolted shear connections. These models were used in a parametric analysis to investigate key parameters such as the thickness of the CFS section, bolt diameter, bolt height and concrete strength. This study highlights the complex behaviour of shear connections and focuses on the interaction of several failure modes that influence the ultimate resistance.