Pivotably detachable hardwood floorboards

A floorboard assembly comprising:

• at least first and second hardwood floor boards adapted to be mounted in a side-by-side coplanar relationship, the first floor board having a tongue extending longitudinally along a first side thereof, the second floor board having a groove extending longitudinally along a second side thereof, the groove having a width defined between a top lip and a bottom lip, the tongue being linearly insertable and removable from the groove while the first and second floor boards are coplanar, the tongue being received in a tight fit manner in the groove, a top surface of the tongue being in frictional engagement with an undersurface of the top lip of the groove from a top outermost contact point to a top innermost contact point relative to a depth of the groove, a bottom surface of the tongue being in frictional engagement with a top surface of the bottom lip of the groove from a bottom outermost contact point to a bottom innermost contact point relative to the depth of the groove, the frictional engagement of the top surface of the tongue depending at least on a distance between the top outermost contact point and the top innermost contact point, the frictional engagement of the bottom surface of the tongue depending at least on a distance between the bottom outermost contact point and the bottom innermost contact point, the frictional engagement of the top and bottom surfaces providing sufficient frictional resistance to resist against translational separation of the first and second floor boards in a common plane thereof when subject to pull-apart forces of a magnitude similar to that encountered during factory sanding operations, the top outermost contact point and the bottom innermost contact point defining a first diagonal, the top innermost contact point and the bottom outermost contact point defining a second diagonal, the first and second diagonals defining slopes of opposite sign, one of said first and second diagonals having a length sufficiently greater than the width of the groove to substantially lock the first and second floor boards against relative pivotal movement in one of an upward and a downward direction associated with said one of said first and second diagonals, a clearance provided between the tongue and the groove, the clearance reducing the length of the other one of said first and second diagonals to approximate the width of the groove to permit an angular withdrawal of the tongue from the groove by manually pivoting the first and second boards toward each other in the other one of said upward and downward directions, and means for providing added flexibility in the bottom lip of the groove, said means including an undercut defined in an undersurface of the bottom lip, the undercut extending substantially along the full extent of the bottom lip in a depthwise direction of the groove.