Building siding unit with interlocking backing board and outer panel

Claim 1

A siding unit for a building or like structure comprising an outer panel and a backing board, said outer panel including spaced upper marginal and butt portions and a face portion extending between said upper marginal and butt portions, said upper marginal portion including a web extending rearwardly of said face portion and terminating in a downturned lip spaced from said face portion, retainer means extending along said upper marginal portion, said butt portion extending rearwardly from the lower edge of said face portion and including an upturned lip, said retainer means receiving in slidable interlocking cooperation the upturned lip of the butt portion of a said outer panel in the upper adjacent siding course, said backing board having front and rear faces and upper and lower edges, the rear face of said backing board terminating spacedly from said upper edge of the backing board to define a lip portion of reduced thickness at said upper edge, said backing board resting upon the web of the upper marginal portion of a said outer panel in a lower adjacent siding course and having its rear face positioned against said structure and its front face located in substantially the same plane as the front face of the backing board in the lower adjacent siding course, the lip portion of said first mentioned backing board being spaced from said structure, securement means connecting said first mentioned backing board only to said structure, said first mentioned backing board only contacting said outer panel in the lower adjacent siding course at said web thereof, said first mentioned outer panel having the upturned lip of its butt portion engaged in interlocking cooperation by the retainer means of said outer panel in the lower adjacent siding course, the downturned lip of said first mentioned outer panel fitted over and behind the lip portion of said first mentioned backing board with said web of the first mentioned outer panel overlying the upper edge of said first mentioned backing board, whereby said first mentioned outer panel is retained in position against said structure by said outer panel in the lower adjacent siding course and said first mentioned backing board.