Metal Roofing Advancements in Providence: A Brief History

Metal roofing has long been the roofing material of choice for commercial and industrial buildings. Its durability, ease of transport, and adaptability have led to the continued success of metal roofing in industry. Over the years, Rhode Island homeowners began to use metal roofing in residential buildings as well, a trend which has only grown in recent years due to advancements in the strength and aesthetic appearance of the materials.

While recent advancements have resulted in a wider range of metal roofing products than ever, it took some time to arrive at the products you see in roofing stores today. Metal roofing systems date back as far as the 3rd century BC. Let’s take a look at the advancements in metal roofing over the years.

Ancient Copper Roofing

As many as 2,300 years ago, in the 3rd century BC, classical civilizations were using copper roofing tiles to provide a durable, decorative finish to their most important buildings. The oldest known example of a copper roof was the Lovamahapaya Temple in Sri Lanka. It was known as the “great copper-roofed mansion” and was famous throughout most of the world at the time for its copper-hued roof. At some point, the temple was destroyed and rebuilt with a bronze roof – an alloy of copper – at which point it became known as the “brazen palace.”

A few hundred years later, the Romans chose copper as the covering for the Pantheon, an important temple completed in the year 126 AD. Similarly, use of the copper alloy bronze continued well into the medieval and Renaissance eras. Copper was chosen for its decorative properties – including its distinctive metallic sheen and gradual black and green patina – its durability, corrosion resistance and its relative strength. In fact, the roof of the Hildesheim Cathedral in Hildesheim, Germany, survived in its original capacity until its destruction in World War II era bombings, despite the fact that it was installed in the year 1240, nearly 800 years ago.

Unfortunately, copper in the magnitude required for an entire roofing system was prohibitively expensive. As such, most societies reserved the use of copper for public, religious, and important buildings. To this point, you’ll find copper and bronze roofs dotting much of the European landscape in the form of cathedrals, churches, and government buildings.

Modern Copper and Lead Roofing

Ever since Americans have been building government and church or cathedral structures, they’ve been covering them in copper or lead. Primarily, the two metals were used in areas where architectural features, pitch, and shapes made wooden shakes or clay tiles impractical. The sheets of copper were originally imported from England for eventual installation on the roofs, although hammered copper continued to find applications in certain areas, but once sheet metal rolling technology came to the United States at the end of the 18th century, sheet metal was produced here.

In fact, the first copper sheet metal rolling facility was opened in 1801 by none other than Paul Revere. Significant projects included the Massachusetts State House, Christ Church in Philadelphia, and King’s Chapel in Boston. All of these buildings were roofed in the late 1700s and did not require re-roofing until fairly recently. People today still use copper roofing for government and other important buildings, as well as in residential installations, though copper is generally too expensive for expansive consumer installations.

Corrugated Metal

Around the same time period, a few manufacturers in the United States had developed a way of forming sheet iron, primarily at rolling mills in New Jersey. Sheet iron was used to cover the roofs of era mansions as well as Princeton University structures that had been destroyed by fire. However, the two main advancements of the time were made in Europe rather than in the United States.

In 1829, English inventor Henry Palmer developed the process of corrugating metal – or adding a series of ridges to strengthen the metal. This strengthened metal was stiffer than regular sheet metal and could be installed over larger areas and lighter frameworks without risk of sagging. The process of galvanizing was also invented to prevent rust. Originally known as CGI or corrugated, galvanized iron, this metal was strong, resistant to corrosion, and easy to transport.

As a result, corrugated metal roofing became a staple building material in such far-flung locales as New Zealand, Australia, and India, all English colonies. The material even became a distinctive part of what’s now known as Australian style architecture.

Eventually, both processes made their way to the United States, as championed by William Strickland, who proposed Philadelphia use corrugated iron to cover the marketplace in that city. By the 1850s, most post offices, government buildings, as well as train sheds and industrial buildings were covered by some iteration of a corrugated iron roof. The practice culminated in 1857 with the re-roofing of the U.S. Mint in New Orleans with galvanized, corrugated iron roofing.

Tin Roofing

When many people think of metal roofing, they think of the classic “tin roof” mentioned in songs and movie lore alike. Even today, when modern metal roofing appears on industrial buildings and homes alike, people refer to the roof as a “tin roof.” However, that is a bit of a misnomer; no roof consists of tin alone.

Tin plated shingles were first produced in Bohemia – modern-day Czech Republic – at the end of the 17th century. Mined in Wales, in the British countryside, tin was exported to several locations to coat, or “plate” rolled steel. Eventually, tin plated iron shingles became more common in Europe and found their way to Canada, where they were used fairly extensively.

Tin shingles did not become popular in the United States right away. First, they were relatively expensive, since they had to be imported from Wales. Second, shingle makers commonly stamped designs into the thin surface of the tinplate, increasing their price due to the aesthetic improvements.

Still, Thomas Jefferson advocated for the use of tin roofing, and had a form of standing seam tinplate roofing installed at his famous home, Monticello. Tinplate shingles were also used on the Arch Street Meetinghouse in Philadelphia. Eventually, tinplate shingles were used on many Victorian-era homes as a longer-lasting, more durable substitute for the era’s commonly used wood shakes and tile.

As the price of tin began to fall following the Civil War, tin’s popularity increased. During this time, people began to devise methods to provide easier installation necessary for the growing number of tin roofs being installed in the U.S. South. Advancements in sheet metal rolling and the development of a tinplate shingle that could be nailed onto a roof drastically increased the accessibility of the product for people who could not afford large sheets of corrugated metal.

These embossed pieces of metal shingle were attractive and could be painted a number of colors. Usually, experts suggested paining embossed tinplate shingles a reddish orange to imitate copper, or adding a finish resembling the green patina of aged copper. With that – a less expensive alternative to the copper roofing featured on important, beautiful government buildings at a fraction of the price and an exceptionally reduced transportation cost due to their lower weight – tin plated steel became a popular roofing material.

Tin Spreads Among U.S. Roofing Materials

The dominant method for tin plating before tin shingles became popular was to “pickle” the metal in a solution of acid to remove rust and corrosion. Then came a series of polishing, rolling, plating, polishing, rolling, and plating and the final product pickled again until a sheet of tinplate was produced. Later, palm oil from West Africa began to replace some animal-based elements of the pickling process, while other improvements and efficiencies in the manufacturing process drastically improved the speed of production.

Further development of tinplate to include individual shingles, standing ridge sheet metal, and embossed strips of tin that appeared to be individual shingles drastically opened up the market for tin roofs of all sizes and price points throughout the United States. By 1860 tin roofs had made it as far west as Arizona. By 1885, a New York company began offering tin shingles backed with a layer of charcoal that reduced the necessity for solder, speeding and cheapening the installation process.

Throughout the early 20th century, tinplate shingles remained a standard means of shingling residential homes, while standing seam and other rolled sheet metal roofs continued to be used on industrial and agricultural buildings. However, with the invention of asphalt shingles toward the beginning of the 20th century, and active government campaigns to replace standard wooden shakes, asphalt shingles became the industry standard by the 1940s.

1940’s and 1950’s – Industrial Buildings

In the 1940s and 1950s, companies began recognizing the utility of corrugated metals to produce large-scale manufactured buildings. Both wall and roof panels were made of the same pre-engineered corrugated steel panels and were rarely painted or made more attractive. However, customers could easily order the prefabricated panels to be transformed into the size building needed.

Most of these buildings were produced for the agricultural, industrial, and mechanical markets. While prefabricated metal buildings proved useful for customers and lucrative for manufacturers, metal roofing became synonymous with industrial buildings at some point during this time. In many areas of the United States, tin roofs became widely known as either “country” or “industrial,” and residential metal roofing fell further out of favor.

1960’s through 1990’s – Industrial Improvements

In 1959, the development of pre-painted metal roof and wall panels led to the drastic aesthetic improvements in the metal industrial buildings that had taken over the metal roofing industry. Simultaneously, development of a much-improved standing seam roofing technology allowed builders to produce buildings with far fewer seams and ridges, resulting in fewer points at which water and elements could enter the building. Fasteners were placed at points above the water grooves of the paneling, further reducing leakage from rain and other elements.

These roofs also allowed for contracting and expanding of the building’s panels, which typically occurs due to changing temperatures. As a result, metal buildings further came into favor in changing climates like the American Midwest. People in colder climates also began to favor metal roofs because snow tended to slide off the smooth surface, rather than gather as in a bitumen, pitch, or standard shingled roof.

By the 1990s, metal industrial building construction had nearly doubled from the previous decades, mostly due to the increased reduction in the price of metal production. Thus, up-front costs for erecting such buildings decreased as well. Maintenance costs proved low as well, and the durability of the metal buildings was proving more so than even the timber-raised barns that had preceded them.

2000’s and Beyond – Metal Roofing Makes a Comeback

By the 2000s, metal building manufacturers and owners alike began exploring the possibilities of making changes to the common, industrial-style metal roofs available at the time. This meant changing the look of the traditional, corrugated or standing seam roofing to more closely resemble the roofing materials people were currently using on homes – asphalt shingles, clay tile, and wood shakes – while retaining the durability of metal.

Currently, most metal roofing materials are made of aluminum, steel or copper. Most often – as it was historically – copper is used sparingly on special features, as it is generally too expensive for whole-roof applications. Steel sheets are galvanized with zinc to prevent rusting, while aluminum sheets do not need this coating. Both are painted, which is then baked on to further prevent rust and ensure a long-lasting finish.

Once painted, the metal shingles can receive nearly any finish imaginable. Some resemble textured, dimensional asphalt shingles and are installed in overlapping sections to enhance the effect. Others are stamped in raised sections to resemble clay tile. Still others are stamped to look like traditional wood shakes or to resemble traditional, standing seam roofs for the nostalgic tin roof fans across the country.

However, all metal roofing on the market today far exceeds the durability, insulative properties, water tightness and soundproofing of its predecessors. Since the early days of copper roofing in the third century BC, metal roofs have been prized for their durability and beauty. That trend has continued over the centuries and millennia among hundreds of changes, upgrades, and advancements, and looks to continue well into the 21st century AD.