Free floating floor system

A free floating hard wood floor system has upper and lower subfloors sandwiched to provide a monolithic panel system which supports the floorboards with optimum rigidity and integrity at a reduced cost. The upper subfloor has grooves milled in the bottom surface with flat clinching strips received within the grooves. The floorboards are disposed above the upper subfloor and secured thereto by a plurality of clinching nails extending through the florboards, the upper subfloor and into the upper subfloor after deflecting on said clinching strips.