Abstract: Decorative wall covering panels are disclosed which sealingly fit against a wall and thereby protect the wall surface from the deteriorating effects of weather. Horizontally and vertically abutting panels which simulate real shingles, such as cedar shake shingles, overlap each other on all edges when installed. Sealing surfaces are provided around the periphery of the inside surface of the panels. The fitting arrangement of the overlapping edges between panels serves to make and maintain the seals between the panels and the wall.

Abstract: Disclosed is a constant contact panel interlock even during thermal expansion and contraction by providing flexible pins to bear on a tongue in a tongue and groove interlock and also by providing ramps for a bendable flange to slide over and bear on. Further, a material made of polypropylene with 20% calcium carbonate filler is used to form the panels, such material being sufficiently flexible at the temperatures common for panels exposed to direct sunlight (as on a roof or wall) to permit the pins or flange to bend without breaking and also being a material of much lower coefficient of expansion than pure polypropylene.