THIN TATAMI MAT

PROBLEM TO BE SOLVED: To provide a thin tatami mat warped rarely and excellent in a machining property by laminating resin boards with the specific gravity of a prescribed value on both faces of a wooden fiber board, and laminating and sewing protective sheets with a cushioning property on both sides to form a tatami base. SOLUTION: A wooden fiber board 1 has the thickness of 5-12 mm and the specific gravity of 0.2-0,4, a resin board 2 is made of polypropylene and has the thickness of 0.5-2 mm and the specific gravity of 0.3-0.9, and the total thickness of a thin tatami mat A is 20 mm or below. A protective sheet 3 is made of a cardboard or a nonwoven fabric having a cushioning property, and it has the thickness of 1-2 mm and the specific gravity of 0.02-0.5. The resin boards 2 and the protective sheets 3 are laminated on both faces of the wooden fiber board 1, and a polypropylene sheet 4 is arranged on the back face and sewn by a vinylon thread to form a tatami base 5. A tatami facing 6 is stretched on the surface of the tatami base 5, and it is wound to the back face and fixed by staples 7. Expansion/shrinkage, a warp or a twist is rarely generated by moisture absorption or drying, and the tatami facing can be satisfactorily fixed by sewing and stapling.