The floor (3) of the loading area (2) in particular of an estate type car or a small van (1) is designed as a sheet (4) of particularly hard steel and can be longitudinally (P) moved along a reinforcing base positioned between the lateral arranged vertical struts (7). The sheet (4) is divided into areas of a higher level of rigidity (H) and such less rigid (W). The alternating areas (H, W) are transversally positioned and extend across the whole sheet (4) in order to facilitate an accordion-like folding (5) in case of an impact.