Abstract: The invention aims to improve a floor for rail vehicles in such a way that an even, level, reference plane for constructing the floor is obtained by a simple tolerance compensation of the deviations in the longitudinal direction, transverse direction and height of the shell assembly. Said compensation is embodied as an easy-to-assemble positive-fit connection between the floor plate and the body-shell floor plate. This is achieved by a retaining profile which is configured as a profile with a recess for accommodating a connecting element and provided with at least one blind opening. An elastic spacer, comprising a plug-in extension to compensate for the existing differences in level between the floor plate and the floor-profile plate, is inserted into the blind opening under pressure, forming a positive-fit. The positive-fit between the blind opening and the plug-in extension is perpendicular in relation to the positive-fit between the profile batten and the retaining profile.