Abstract: A panel assembly for use in construction of flooring, walls or ceiling has two panels (1, 2) each having a planar surface (3, 4) on one side and one its opposite side (5, 6) a plurality of bosses (7, 8) projecting from the panel. The panels (1, 2) are interconnected by abuttment of the bosses (7) of one panel (1) with the bosses (8) of the other panel (2) and a locking member (12, 18) is associated with some of the abutting bosses to thereby prevent lateral movement of panel (1) relative to the other panel (2). The locking members (18) may be tubular and/or comprise locking pins (12) arranged to pass through bores in some abutting bosses. When used as a flooring the panel assembly is installed on a concrete base (26) having a substantially flat surface and bedded on an adhesive compound (25). A number of panel assemblies will be required to construct the flooring wall or ceiling, but once constructed a number of individual panels may be removed to readily allow the installation of mains services.