Abstract: Panel siding for the wall of a building comprising elongated panels arranged in close, parallel relationship with the longitudinal edges of adjacent panels opposed to one another. The panels have integral tongue and groove formations along the opposed longitudinal edges which are interengaged to provide connections between panels. A layer of insulation is provided at the rear of each panel, providing a panel insulation unit. Each panel insulation unit is installed in a single step.

Abstract: A mounting system for plastic siding comprises an elongated nailing strip from which a siding panel is suspended by means of interlocking channels which permit longitudinal relative movement resulting from differential thermal expansion or contraction. A predetermined amount of horizontal overlap of adjacent panels is assured by the provision of a notch adjacent each end of the panel, which notch is intended to be vertically aligned with the end of the adjacent panel. The same notches provide a guide for centering the nailing strip on its associated panel. Unintended disassembly of each strip-panel pair is presented by dimple-like deformations near the end of each strip cahnnel, which function to limit the longitudinal travel of the associated panel channel therein.