Abstract: A hardwood floor structure includes a piece of sponge, a plurality of plastic E-shaped racks with apertures and ribs extending upward, and a plurality of rectangular floor boards composed of an upper portion, an intermediate portion having a protruding flange extending from two adjacent lateral sides and a recess on another two adjacent lateral sides such that the protruding flange is configured and sized to engage with said recess, and a lower portion having an inclined upper edge along a longitudinal side, an inclined lower edge along another longitudinal side, and a shoulder above the inclined lower edge. The ribs on the E-shaped racks have an enlarged head with an inclined surface forming a lower projection to be positioned on the shoulder of a respective one of said floor board. The rib has an upper projection at the other side to be positioned on the inclined upper edge of a respective floor board.

Abstract: An improvement in the structure of a hardwood floor includes a piece of sponge, a plurality of floor boards each being a generally rectangular member composed of an upper portion, an intermediate portion and a lower portion, said upper portion having a top surface for walking, said intermediate portion having a protruded flange extending outwardly from two adjacent lateral sides thereof and a recess on another two adjacent lateral sides thereof, said protruded flange being configured and sized to engage with said recess, said lower portion having an inclined upper edge along a longitudinal side thereof, an inclined lower edge along another longitudinal side thereof, and a shoulder above said inclined lower edge, a plurality of plastic racks with an E-shaped cross section having a plurality of ribs extending upwardly from a top thereof, each of said ribs having an enlarged head with an inclined surface thereby forming a lower projection at one side adapted to be positioned on said shoulder of a respective one