Metals used for architectural purposes include lead, for water pipes, roofing, and windows; tin, formed into tinplate; zinc, copper and aluminium, in a range of applications including roofing and decoration; and iron, which has structural and other uses in the form of cast iron or wrought iron, or made into steel. Metal alloys used in building include bronze (mainly copper and tin); brass (copper and zinc); monel metal and nickel silver, mainly consisting of nickel and copper; and stainless steel, with important components of nickel and chromium.
The low melting point of lead permitted its use on a wide scale throughout human history. Lead was one of the first to be made into sheet metal for architectural purposes. Water pipes were frequently constructed of lead, until its health hazards were publicised in the late 19th century.
Lead is not subject to rust and has been a popular roofing material for centuries, being used for roofing, flashing, gutters, downspouts, and conductor heads. Lead was best suited for low-pitched roofs, as steep roofs experienced creep. Lead roofs in regions with large temperature fluctuations, such as the mid-Atlantic states, experienced deterioration from constant expansion and contraction, called fatigue. Beginning in the 19th century, a roofing material called “terne” or “terneplate” was used, consisting of sheet iron or sheet steel coated with a lead-tin alloy. It is frequently confused with tinplate.
Lead came was also frequently used for window panes in skylights and stained glass. It was also used for small pieces of sculpture and garden ornamentation. Lead was frequently added to paint, with red lead used as an anti-corrosive pigment for iron, and white lead used as paint for wooden houses. Lead-based paint was one of the most durable materials developed as a protective exterior coating. The use of lead paint has been restricted on most buildings, due to concerns of lead poisoning.