Perforated load-bearing clay masonry walls are a very efficient construction system, with a very favorable resistance-to-weight ratio, allowing rather thin load-bearing walls (typically 12 to 14 cm, as used in Belgium or in the Netherlands). However, due their limited surface mass, additional devices must be implemented in those walls when used for instance for apartment buildings, in order to reach the requirements in terms of acoustic insulation. Those devices are rubbers layer with a thickness of 1 cm located at the base, and if needed at the top, of the walls in order to cut the vertical transmission of acoustic vibrations. Although not aiming at improving the seismic behavior of the walls, these flexible layers do however modify significantly the stiffness of the wall and hence its dynamic properties, acting as a kind of partial seismic isolation and also possibly shifting a shear failure mode to a rocking behavior. The present contribution summarizes the findings of an experimental program aiming at characterizing the cyclic behavior of such a system submitted to in-plane horizontal loads.