Plastic siding mounting system

Claim 1

In a mounting system for building siding of the type wherein a panel of horizontally elongated thin-walled siding is adapted to be suspended from a horizontally disposed and elongated attachment strip by means of interlocking channel formations on the upper portion of the panel and on its associated attachment strip when the attachment strip is secured to an underlying wall structure, and wherein the panel is longitudinally slidable relative to the strip following installation to permit the panel and strip to thermally lengthen or shorten relative to each other as a result of their different coefficients of thermal expansion when exposed to changing ambient conditions, the lower edge of each panel overlying and interlocking with the interlocking channel formations of the next vertically adjacent lower panel course and attachment strip, the improved means for establishing the proper horizontal overlap of horizontally adjacent panels at the time of installation which comprises: each of said panels being fabricated with a panel overlap mark on the upper portion of said panel and spaced from a longitudinal end of said panel by a predetermined distance equal to the preferred length of overlap, said mark being located so that it will be obscured from view by said overlying lower edge of the next vertically adjacent course of the panels following installation thereof; whereby said panels may be accurately positioned at installation by longitudinally overlapping a first panel over a previously secured horizontally adjacent second panel to an extent such that said overlap mark on one of said first and second panels is in substantial vertical alignment with the longitudinal end of the other of said first and second panels.