horizontal furthermore when the above mentioned floor base 1 is made of wood such as plywood etc the self levelling material may not be used or a level adjusting plate not shown in drawing may be used to form a horizontal surface it is preferable to cover the above mentioned floor surface 3 with calcium carbonate paper having hygroscopic property as an underlay material 4 when the tiles are applied and fixed on the underlay material 4 the material 4 makes the removal of the tiles from the floor easy furthermore when the floor base is made of wood the underlay material 4 can be released from the effects of expansion and contraction of the wood on the whole upper surface of the underlay material 4 a sheet 5 having pertinent elasticity is applied as shown in fig3 the sheet 5 is prepared by forming a coating layer 52 by use of rubbers synthetic resins or foamed type thereof with high elasticity on a net like knitted core material 51 made from glass fibers or strands of synthetic resins on the sheet 5 as shown in fig1 and fig2 substantially square earthenware tiles 6 are set side by side in sequence from the peripheral partition face of edge portion of the floor surface 3 not shown in drawing at this time the whole peripheral sides of each tile 6 is surrounded with a joint material 7 the joint material is made of elastic foamed resin material formed in.