possible with the intended mounting if a facing tile become broken or defaced it can be replaced by pulling it from its mounting and replacing it with a new one also because of the potential for replacing tiles individually the backing member must be solidly connected to the substrate to prevent separation when a tile is removed accordingly the backing member may be nailed or screwed to the wall it will be observed that the prong 34 includes an enlargement 36 near its end which is larger than the opening 22 when the enlargement 36 is pushed through the opening 22 the slits will allow the flaps 25 to flex out of the way until the enlargement passes through the hole then the flaps will flip back into place to releasably lock the backing member and tile together see particularly fig3 at this point the patterned relief 20 32 of the two elements will be in nested position and the combined heighth of the two will be about 1 2 inch from the substrate surface it will be observed that relative dimensions of the length of the prong 34 thickness of the enlargement 36 and the thickness of the flaps 25 are critical to the proper functioning of the tile mounting process the flaps are relatively thin so that the prong 34 can penetrate the.