AbstractThe change in the structural and physical properties of the components assembled in a fuel cell stack, when being compressed, is important for performance evaluation. The physical properties of Gas Diffusion Layer (GDL) materials, such as thickness, through plane resistivity and gas permeability and pore size data are presented as a function of compressive force. The data obtained are correlated with fuel cell performance data. Beyond the materials and components specific properties the behaviour of combinations of BPP and GDL materials, which are manufactured by SGL Technologies GmbH, are evaluated and presented. Through plane resistance of a GDL‐BPP‐GDL sandwich is evaluated for varied compression forces and materials permutations.