Molded plastic siding units

Claim 1

The combination of a plurality of generally rectangular weather-resistant plastic siding units adapted to be affixed to a building with similar units in overlapping horizontal courses with the units of each course lying in closely adjacent edge-toedge overlapping relation and with them simulate the appearance of overlapping butt-exposed courses of conventional wooden siding elements, each of said units comprising: an integral hollow-backed self-supporting piece of molded rigid plastic formed from sheet material of uniform thickness presenting a weather-exposed ornamental exterior relatively stiff main panel portion: reinforcing side edge portions rearwardly extending from said main panel portion of the units with each of said edge portions having means formed to overlap and cooperate respectively with opposing side edge portions of adjacent similar units of the same course to prevent ingress of rain between said side edge portions and their adjacent similar units, said side edge portions including flat parallel rearwardly extending planes generally perpendicular to the plane of said main panel portion but tapering in increasing depth from the tops toward the bottoms of said side edge portions with one side edge portion providing an inwardly extending tongue and the other an outwardly facing groove interlocking with the tongue of a like unit of the same course, said groove being wide enough to limitedly horizontally slidably interlock with the tongue of a like unit of the same course with clearance therebetween to allow for horizontal temperature expansion and contraction of the assembled units, reinforcing top and bottom edge portions rearwardly extending from said main panel portion of the units with the bottom edge portion providing a substantially plane weather-exposed offset butt at about a right angle to said main panel portion, said top and bottom edge portions having means interlocking with similar units of adjacent horizontal courses above and below to prevent ingress of rain therebetween, with said top edge portion of the units having a downwardly and outwardly directed parallel open reentrant recess with spaced parallel edges, an opposing male rib thereabove facing, and forming a part of, said reentrant recess being formed to retain in interlocked position the terminal bottom edge of a similar unit of an adjacent next higher overlapping course and to prevent windlifting of such bottom edge and its adjacent offset butt and a terminal upwardly extending nailing flange above and beyond said recess and rib, said bottom edge portion terminating in a downwardly and outwardly directed hook limitedly vertically slidable in the reentrant recess of an adjacent next lower course of said units with clearance therebetween to allow for vertical temperature expansion and contraction of the assembled units.