Abstract: A square panel includes base of expanded polystyrene, and has two adjacent sides with projecting edges adapted to mate with the undercut sides of two identical adjacent panels. All four sides of the base are preferably bevelled, and the front face defines intersecting grooves so that a polymer fortified concrete facing can be applied to the front of the base without warping the base as the concrete shrinks during hardening. An acrylic binder, preferably with quartz granules carried therein, is provided over the concrete facing to enhance the appearance of the panel, and to improve its resistance to impact. The panels are assembled to an existing wall structure or the like by applying mastic to the rear face of the panels, and a strip of foam expanded polyvinyl chloride tape of the nonporous variety is adhered to the adjacent edges of the panel which define the projecting portion thereof so as to facilitate assembling of the panels and to provide a water tight exterior wall.

Abstract: A fuel storage tank of welded steel plate design is insulated by first providing a structural layer of expanded steel mesh or lath welded to the exterior tank wall by welding washers, and then applying gobs of a cementitious mastic to hold foam heat insulating boards to discrete areas of the lath layer. An outer layer of fiberglass reinforced resin provides a durable yet pliable outer finish for the tank, and also imparts tensile strength to the resulting insulating structure.