Patent ID: 8347573

Claim:
A combined ceiling and floor structure, comprising: floor joists and a single set of adjacent boards; wherein said floor joists span between walls of a first room and a second room; wherein each adjacent board has a first surface, a second surface, a first lateral edge and a second lateral edge; wherein each adjacent board includes a softwood layer bonded to a hardwood layer; wherein said first surface is softwood and said second surface is hardwood; wherein said first lateral edge has a tongue; wherein said second lateral edge has a groove; wherein said first and second lateral edges have a chamfer on said first surface; wherein said softwood is laid towards said floor joists; wherein said adjacent boards are secured to said floor joist with said tongue in said groove; wherein each adjacent board has embedded sound attenuating elements; wherein each embedded sound attenuating element has a first side and a second side; wherein all first sides of said sound attenuating elements are covered completely by said first surface of softwood; wherein all second sides of said sound attenuating elements are covered completely by said second surface of hardwood; wherein each adjacent board has transverse stiffening elements embedded therein; wherein said transverse stiffening elements are milled to coincide with the location of said floor joist to which said board is secured; and wherein said sound attenuating elements are a continuous layer of sound attenuating material.