The slab is designed to be applied on a raised-access floor or for its positioning on the deck as a high raised-access floor. This slab has optimal characteristics as regards fire resistance by virtue of its particular configuration, and protection against breakages, wear and abrasion, in particular during its handling and assembly and fundamentally comprises a core (1) which is coated in its edges by a layer of thermosetting resin (2), and metal supports (3) which emerge from the lower surface of the core (1) which determine an elevation of the core (1).