Patent ID: 8402707

Claim:
A siding panel system of a building comprising: a pair of elongated panels in a lower panel row comprising cellular polyvinylchloride coupled at adjacent vertical ends with outer faces of the panels together providing a substantially planar lower row outer surface with an outer seam portion; a first elongated panel of the pair having on a vertical end an integrally formed first interlock including a first projection adjacent a first receiving groove at said outer seam portion; a second elongated panel of the pair having on a vertical end adjacent to the vertical end of the first elongated panel a corresponding integrally formed second interlock including a second receiving groove and second projection mated to the first projection and first receiving groove, wherein the second interlock forms an inward seam portion in an inward surface opposite from the substantially planar lower row outer surface and the inward seam portion is offset from linear alignment with the outer seam portion; fastening flanges disposed along upper horizontal edges of the first and second elongated panels with the flanges coupled to an underlying building surface such that the first and second elongated panels undergo horizontal lower row movement as a single unit during shifting, contraction or expansion; an upper row of a plurality of elongated panels coupled to the underlying building surface with their outer faces together providing a substantially planar upper row outer surface and the upper row horizontally interlocked along lower horizontal edges to the upper horizontal edges of the pair of first and second elongated panels allowing said lower row movement and disposing the upper row outer surface in a substantially parallel and different plane from the lower row outer surface; and a decorative end piece coupled to the building and covering a vertical edge of one of the first and second elongated panels opposite a vertical end at the inner or outer seam portion wherein the vertical edge is free to move horizontally as an end of the lower row behind the decorative end piece.