Abstract: A building slab is disclosed which is mountable on a support structure and capable of supporting a fixed or mobile load. The slab includes a base structure having a plurality of parallel planks, rectangular in cross-section, and assembled together with nails or screws. The planks have their longitudinal axis parallel to a plane of the slab, and are alternately offset with respect to one another and perpendicularly to the plane of the slab. The base structure is covered, at least over the entire surface to receive the load, with a continuous panel which extends over its entire width and is fixed at least against a top surface of the planks so that the load exerted on the panel is distributed over several lateral planks adjacent to those against which the load is directly exerted. The distribution of the load is along an axis perpendicular to the planks and parallel to the direction in which the planks are nailed or screwed together.