Metal Roofing

Who Invented the Original, Corrugated Iron / Steel Roofing Style?

Henry Robinson Palmer learned his civil engineering under Scotsman Thomas Telford, the greatest builder of roads, canals, and bridges in the British Empire in the early 19th century.

In 1821 Palmer applied for a patent for a single elevated rail supported by pillars spaced ten feet apart that sported wheeled carriages hanging down from either side that would roll along the rail when pulled by a horse. Henry Robinson Palmer had invented the world’s first monorail.

If you research Palmer’s life today, every source details the creation of the monorail. For most thumbnail sketches of Palmer’s life that is the end of the story, but Palmer himself did not concern himself much with the monorail after building the first one in 1825, about one mile long, in Cheshunt, a town twelve miles from London.

Two years later the 32-year-old Palmer landed a job as resident engineer for the London Dock Company. It was his responsibility to construct the walls along the Thames River to keep the world’s busiest port humming.

The aging wooden docks were in constant need of upgrade. To keep up Palmer patented a lightweight metal building panel that was self-supporting due to a series of waves or folds molded into the sheets.

Palmer’s manufacturing process consisted of pushing his sheet metal across fluted rollers to create the ridges that gave the metal strength. He called this “corrugation”, from the Latin word for “wrinkled.” It remains a common method for manufacturing corrugated metal today.

Palmer erected the world’s first corrugated building on the Thames River docks in 1829 and he continued to patent improvements in the construction of arches and roofs.

It is ironic that today Henry Robinson Palmer is remembered for the invention of the monorail, which is rarely encountered outside of amusement parks, airports, and a classic Simpsons episode. He is scarcely recognized for the development of corrugation, which became so ubiquitous in the 19th century for cheap shelter that most people – and historians – assumed it had been with us since antiquity.

Historical Significance of Corrugation

Without corrugated metal there would have been no rapid development of the United States frontier, a less frantic California gold rush, much slower settling of farmland on the Great Plains and much harsher living conditions on the battlefield.

The strength to materials imparted by corrugation extended beyond the sheet metal shop to other industries; it was critical to the development of the cardboard, for instance.

Metal Roof Construction

By stiffening the metal sheets, corrugation permits a greater span across a lighter framework, ideal for the balloon construction techniques that became widespread in the 19th century.

However, metal for roofing has been used for centuries, although it was rare in early America. Thomas Jefferson was a metal roof fanboy and installed tin-plate iron on the roof of his beloved Monticello in rural Virginia.

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