This section is from the book "A Treatise On Architecture And Building Construction Vol3: Stair Building, Ornamental Ironwork, Roofing, Sheet-Metal Work, Electric-Light Wiring And Bellwork", by The Colliery Engineer Co.. Also available from Amazon: A Treatise On Architecture And Building Construction.
This kind of a gutter, for a fireproof building, is shown in Fig. 35. The terra-cotta slab a of the cornice is backed by brickwork b, upon which rest the I beams c of the roof trusses. The usual angle or T iron purlins support the porous terra-cotta slabs. The mason fills in the gutter bed e with cement concrete and grades it to the proper pitch. The sheet metal, which is generally 16 or 18 ounce soft or hot rolled copper, is then bent up and laid into the gutter, the front edge being bent down into a groove f, which is molded in the terra cotta, and the back edge is run up the roof and overlapped by the slates or tiles in the usual manner. The connection between the copper and the terra cotta is made water-tight by filling the groove full of molten lead, which, when cold, is solidly batted with a hammer and calking tools. If this method of attachment is not desired, the cornice may be molded with a dovetailed projection, so that the metal may be sprung over it as shown in Fig. 36. This will hold the copper down, but it is not as solid as the calked joint shown in Fig. 35.