Original roofing trade vintage catalog for H. H. ROBERTSON COMPANY. Main office was located in Pittsburgh, PA. Manufacturers of protected metal for roofing, siding, flashings and general building trim. Cutaway section showing the steel core sheet, asbestos felt, asphalt, and steel. There are two pages of general drawings which illustrate the four types of buildings most often used in industry. The last five pages are enlarged drawings to show close-ups of various vital spots on the buildings which were pictured on the first two pages, together with sections not shown on those index pages. Unbound from a large 1931 architectural catalog, this unique old nine page technical specifications brochure would display beautifully matted and framed. A fantastic addition to your retro roofing construction library. Pages are detached and contain a small amount of residual glue on edge.