such as a floor or wall of any type for example in a bathroom or in any other room in a house or other building the many possible uses of the invention will be clear to those who read this description of the invention an assembly embodying the invention includes a frame or grid 10 which is of any desired size or shape and is adapted to be secured to the above mentioned support surface by screws or the like inserted into holes 12 in one of the most appropriate uses of the invention the frame 10 is secured to a wall the frame is preferably made of a light metal wood or plastic of the like and includes vertical arms 20 and horizontal arms 30 both of which are provided with slots 40 along their lengths the slots have a base 62 and side wall 64 according to the invention tiles 50 are provided overlying the openings in the grid which may be in the form of rectangles or the like formed by the horizontal and vertical arms of the grid the tiles are secured to the frame or grid as follows the tiles have bent down horizontal and vertical edges which are adapted to fit into the slots formed as seen in fig3 in one form of the invention in order to secure the edges of the tiles in the slots.