A tile for use in the construction of a false floor consists of a rectangular tray (10, 20) into which concrete (14) is poured. The tray is of metal, a strong plastic material or any other suitable material. The concrete is preferably pliable concrete. The tray has a diagonal ridge (13, 23) which has a cross-sectional shape of a narrow inverted V, extending into the concrete. Preferably the tray has at least one shear pin extending from the floor (11, 21) of the tray into the concrete, to reinforce the bond between the concrete and the material of the tray. The side walls (12, 22) of the tray may be shaped to provide an additional key for the concrete, which also reinforces that bond. To form a false floor, the tile is placed on pedestals located under each corner of the tile. If the tops of the pedestals are not coplanar, pressure on the upper surface of the tile causes the triangular portions on each side of the ridge to move relative to each other about the line of the ridge, until all four corners of the tile contact the tops of their associated pedestals.