The signature shape of corrugated metal is the key to its durable, yet lightweight, characteristics which make it the perfect choice for many construction projects.
In the same way that the paper that makes up a cardboard box is strengthened by the sheet of wavy paper sandwiched between two flat layers, sheets of metal can be made stronger by corrugating, or folding the material to make ridges and grooves. The wavy construction leads to increased strength over a shorter surface area.
This special corrugated shape adds strength to lightweight materials. This means that a lightweight metal like aluminum, which may otherwise be too flimsy, can be made sturdy enough to withhold years of beating in all kinds of weather.
While this type of roofing has traditionally been used in commercial, industrial, and farming settings, residential homeowners have recently increased the demand for the product. Additional improvements such as galvanized metal, which protects it against corrosion and rust, has allowed this sheet metal roofing to evolve from a limited material into one of the most sought-after roofing materials available.
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Corrugated metal roofing is most commonly available in copper, aluminum and stainless steel. If you were to get a roofing quote with these different materials, you would most likely find that these three metals differ in appearance, cost and durability.
Corrugated aluminum roofing is at the top of the list in terms of both value and quality. For this reason, aluminum is preferred in residential settings. As an added bonus, aluminum roofing is durable, rust resistance without the need for additional coating, better looking, and can take on different paint colors.
Corrugated steel roofing sheets come with a built-in, natural gray finish to them. While this may work in some instances, many owners wishing to change the initial color of the material may run into problems. Corrugated steel roofing is also more expensive than the other two most common alternatives.
Another alternative that has not been talked about much is corrugated copper roofing, which while easy to install and naturally resistant to rust, usually turns out to be the most expensive option. In rare occasions, metal alloys are used to make corrugated sheet roofing, however the cost of alloys makes this type of roofing financially prohibitive.
Corrugated Roofing Characteristics
With all the properties that metals have, it is not uncommon for a metal roof to last for up to 100 years. It would make sense that a roof of this material would be able to withstand extreme weather conditions, including heat waves, snowstorms, hurricanes, and even hail storms. The most modern galvanized metal roofing also has fire resistant properties, and contrary to popular belief, is your safest option in areas where lightning strikes are common.
Those who are concerned with being environmentally friendly would be happy to know that corrugated roofing is completely recyclable. In warmer climates, metal roofing reflects the sun and reduces air-conditioning bills, while in cooler climates it can warm underlying areas. Its lightweight build reduces stress on the underlying walls of buildings, and so doesn't require much structural support. When installed properly, leaks should never be a problem like they are with traditional roofing shingles.
Corrugated roofing is still widely used in many rural areas, as well as military communities. Its ability to be easily transported, along with its lightweight properties, have been reasons why countries like Australia adopted its use as far back as the 1840s.
History of Corrugated Roofing
Corrugated roofing was invented by the British architect and engineer Henry Palmer, who worked for the London Dock Company. It was originally known as CGI, which stood for corrugated wrought iron. In its earliest form, CGI exhibited strength, corrosion resistance, and convenient transportation, all of which led to its desirability in the production of prefabricated structures by skilled workers. Soon thereafter, CGI became known as a staple construction material in the United States, New Zealand, Australia and India, to name a few. During the 1900s, Australia adopted corrugated roofing as part of the attractive architecture that became a piece of their cultural identity.
Up until around 1900, corrugated sheet metal roofing was mainly only used for commercial and industrial purposes. A drive through an agricultural or industrial area of America or Australia would commonly bring about scenes of buildings built with wavy, corrugated roofing that often times had signs of rust on it. Nowadays, technology has brought about desirable properties that include rust resistant features, which is a large reason why the roofs have made such a comeback in the residential sector.
In terms of construction, the corrugated sheets are laid similar to the method used with tiled shingles, where an overlap exists between two or three neighboring sheets, with each overlap measuring about 150 mm. This overlap, when performer properly, makes corrugated roofs completely waterproof.
In the corrugation process today, roofers utilize a method called roll forming. This is a highly automated process that is good for reducing costs that come with labor, and consequently increasing the efficiency involved in production. Other parts of the sheet-making process include pulling off large rolls of corrugated metal through rolling dies that are responsible for the recognizable waves that this type of roofing is known for. While the waves are usually rounded, different shapes and sizes can be achieved simply by changing the dies.
Corrugated Metal Roof Benefits
Corrugated metal roofing system is best used on buildings that either have steep slopes or get rid of water quickly. You would think that a metal roof would be noisy during rainfall, but surprisingly this is not the case. If you are inside a home that uses corrugated roofing, the amount of noise you hear during rainfall is similar to what you would hear from a roof made of asphalt or clay.
Taking into account that a galvanized roof won't rust, and that a corrugated aluminum roof or corrugated steel roof will last for up to 100 years, there are not many downsides to owning this type of roofing.
Other benefits include resistance to rot and lack of vulnerability to insects such as termites. Most of these roofs are also treated with chemicals that prevent the growth of algae. In communities that are prone to wildfires, metal roots can provide a safe haven because of their noncombustible properties and Class A fire ratings.
Finally, their lightweight nature lightens the load on installation and underlying building structures. All of these properties lend themselves to the idea that corrugated metal roofing is as close to a perfect roofing material as there is. The value that comes with the durability, and the flexibility that comes with the ability to change its color and appearance, along with the quality that comes with all of its additional desirable properties, makes corrugated roofing one of the best values for your money.
Disadvantages to Corrugated Roofing
The biggest downside to corrugated roofing before the advance of galvanized technology was the rust. Many homeowners and commercial building owners can't be blamed for thinking this, because in older buildings that used corrugated roofing, the rust can easily be seen. However, as mentioned earlier, manufacturers have used current technology to get rid of rust and corrosion problems, thus increasing the demand for the product. Now, the modern corrugated roofing sheets not only have rust resistant properties, but appeal to the aesthetic look that builders and owners are looking for.
There are, however, a few issues that you might want to be aware of. Denting in the corrugated sheet metal is an issue which is hard to stay away from. Besides the occasional bumping and bruising, hailstorms have been known to cause dents in corrugated metal roofs.
The expense of installation, while offset by the low cost of maintenance work required, is also a barrier for some people looking into corrugated metal roofing. If you are not convinced that noise is a non issue, you can always make sure that a layer of insulation lies underneath the metal sheet during installation. Like all roofs, time will produce scratches and chipping. If a layer of paint is applied on top of the metal, peeling and fading may also occur over time.