Tin Roof

A true tin roof is made of tinplate: thin iron or steel sheet coated with tin. Very few modern roofs fit that description, but the phrase lives on as an everyday label for metal roofs in general, including galvanized corrugated steel, coated steel panels and even aluminium.

Historic tinplate roofs

Tin roofing was used widely in Canada in the eighteenth century and became common in the United States somewhat later. Thomas Jefferson put a standing seam tin roof on Monticello in the period around 1770 to 1802, and the Arch Street Meetinghouse in Philadelphia (1804) had tin shingles laid in a herringbone pattern. Once American rolling mills were operating, tinplate became the most common roofing metal because it was cheap, light and needed little upkeep. Embossed tin shingles were popular in the late nineteenth century.

Tin roofs were kept well painted, usually red. Because the base metal is iron, preservation guidance calls for priming the underside and maintaining the paint on top.

Tin versus terne

Historic records often confuse tinplate with terne plate, which used a cheaper lead-tin coating and has a duller finish. Both were installed with flat seams or standing seams and soldered joints, and both were eventually replaced in new construction by galvanized and aluminium-zinc coated steel, copper and terne-coated stainless steel.

Modern usage

Speaking of a "tin roof" today usually tells you only that the roof is metal. For repair, insurance or conservation work it is worth identifying the actual metal and coating, since compatible materials, fasteners and solders differ.