Abstract: A vinyl siding panel which includes a top lock, a medial main body portion, a bottom lock, and a nailing hem adjacent the top lock comprises a channel with nail apertures in the channel base for receiving siding nails. The channel has an open end which has a dimension smaller than the nail head diameter so that the nail head bears against shoulders or bearing surfaces formed adjacent the channel. The channel can be of rectangular or tapered cross-section in order to space the nail head away from the nail apertures and thereby eliminate stress concentrations at the apertures. The lock structures are generally complementary in shape so that they interlock with other siding panels of like construction. The panel can be reinforced along its length for added rigidity. One area of reinforcement is the channel nailing hem which can be reinforced by extruding additional material to form the channel or by providing an elongated trough-like insert nested within the channel.

Abstract: A plastic siding panel which includes an upper connector, a medial main portion, and a lower connector. The connectors are complementary in shape so that they interlock with other siding panels of like construction. At least one of the connectors include a strip of high strength material for rigidifying the siding panel. The siding panels are fabricated by extruding a monolithic, substantially planar sheet composed of three different materials. Two of the materials are formed as layers which extend over the entire sheet. The third material is a high strength material adapted to rigidify the siding panel. After extrusion, the sheet is formed into a siding panel having a main portion, an upper connection and a lower connection.