Abstract: A siding panel with a cover sheet of hardboard fixed by an adhesive to an underlying backerboard of resin foam. Preferably the panels are installed with their longitudes extending horizontally. Each panel is secured to a wall frame by nails passing through spaced apart holes through the cover sheet adjacent its upper longitudinal edge and a locking structure adjacent the lower longitudinal edge of the panel. In the first course of panels the locking structure engages a starter strip nailed to the wall frame and in each succeeding course of panels engages the upper edge of an adjacent panel in the immediately preceding course. The locking structure is a tongue and preferably an adjacent recess in the lower longitudinal edge of the backerboard which when installed receives and interlocks with the upper nailed edge of the cover sheet of an immediately adjacent panel or a flange of a starter strip simulating an upper edge of a panel.

Abstract: A composite interlocking siding panel includes an elongate sheet metal or vinyl outer panel having a nailing strip along one longitudinal edge and mating interlocking means extending along each longitudinal edge. An elongate boardlike member of insulating material is bonded to the back of the outer panel. The insulating member is so configured that it may be of any selected thickness without interfering with the installation of the composite panel on a building wall. The insulating member includes a projection extending along one longitudinal edge which projects beyond the nailing strip and is configured, when installed, to snugly fit within an undercut recess in the mating longitudinal edge of a like interlocked panel with the rear surfaces of the insulating members lying in a common plane in their finally installed position.

Abstract: A backerboard for use in conjunction with a siding panel of the type having longitudinally disposed walls connected by a longitudinal step and wherein the siding panel is normally fastened to the external wall sheathing of a building. The backerboard is adapted to be disposed between the inner surfaces of the siding panel walls and the exterior of the building sheathing. The backerboard is fabricated from two polystyrene foam plastic members that are disposed with respect to each other so as to have overlapping portions that are bonded to one another by a suitable adhesive such that the longitudinal side edge of one of the members adjacent the overlapping portions is contoured to snugly abut the step of the siding panel when the backerboard is positioned against the same. A method for manufacturing the backerboard is disclosed.

Abstract: A backerboard for use in conjunction with a siding panel of the type having longitudinally disposed walls connected by a longitudinal step and wherein the siding panel is normally fastened to the external wall sheathing of a building. The backerboard is adapted to be disposed between the inner surfaces of the siding panel walls and the exterior of the building sheathing. The backerboard is fabricated from two polystyrene foam plastic members that are disposed with respect to each other so as to have overlapping portions that are bonded to one another by a suitable adhesive such that the longitudinal side edge of one of the members adjacent the overlapping portions is contoured to snugly abut the step of the siding panel when the backerboard is positioned against the same. A method for manufacturing the backerboard is disclosed.