Choosing a metal for architectural cladding

Galvanized steel provides an ideal combination of cost and corrosion resistance for an exterior.

Although expensive, metals are the most durable material used for cladding in residential and commercial construction. Some are commonly used throughout all of manufacturing and construction, such as the ferrous metals, whereas others usually have specific niches, such as titanium and red metals.

Because it's abundant and not very expensive, iron is among the most commonly used metals for industrial purposes. Just a small amount of carbon and a few other elements turn it into steel, a family of metals with an abundance of favorable characteristics. Regrettably, the iron combines readily with oxygen to form rust; thankfully, just a thin coating of zinc is all that's needed to provide an impressive resistance to corrosion.

A bonus is in the aesthetics. Galvanized steel develops visible crystallite patterns as a result of the zinc bonding with the steel. Cladding made from galvanized steel is a durable, eye-catching feature for exterior applications, especially for contemporary designs.

Like common carbon steel, stainless steel comes in many varieties. By varying the combination of the main alloying elements—chromium, molybdenum, and nickel—manufacturers optimize its corrosion resistance and its hardness (to vary the ease of machining and forming). The chromium reacts with oxygen, but it's not a progressive reaction; the reaction comes to a stop at the surface and the material doesn't degrade or deteriorate.

Cladding made from stainless steel gives any surface a clean and polished finish. These are great for both indoor and outdoor applications of modern buildings.

Known for its striking appearance, weathering steel is a favorite of many professionals in the construction industry. Initially marketed as COR-TEN, the consistent rustlike patina that develops over time is actually a protective layer that keeps the material from corroding. It also eliminates the need for repainting.

Weathering steel lends a rustic appearance to industrial-style homes and buildings.

Aluminum is another favorite metal to use in the manufacture of cladding materials. It boasts an excellent strength-to-weight ratio, allowing manufacturers to create panels that are less bulky but as strong as their steel counterparts. Also, aluminum acts like chromium. It bonds readily with oxygen to form a thin, hard layer of aluminum oxide, which protects the underlying material.

Aluminum cladding is suitable for contemporary and commercial construction projects. It needs to be installed and maintained by professionals because the material isn't as hard as many other materials, leaving it prone to dents and scratches.

Cladding made from titanium is a favorite because of its glossy and reflective surface. More than that, the metal is extremely durable and strong despite being lightweight. To make the material corrosion-resistant, manufacturers give it a protective oxide film. Once installed, the titanium cladding needs regular maintenance and cleaning to prevent damage.

Stainless steel provides a dramatic look and needs little maintenance.

Zinc is well-suited to cladding because it has immunity from the harmful effects of the sun's UV rays, has amazing corrosion resistance, and has a weatherproof surface. Best of all, this metal has self-healing properties, meaning scratches "heal" and disappear as time passes by.

Cladding materials made from zinc or coated with zinc are perfect for exterior applications.

Another durable metal used to manufacture cladding materials is copper. It is known for its beautiful reflective surface that oxidizes and develops a distinct green patina over time. This makes copper cladding recyclable. Sometimes people buy the copper cladding used in buildings before the structures get demolished.

Another metal alloy that develops a beautiful patina over time is brass. Cladding material made from brass is lustrous, then takes on a golden-brown patina as the surface oxidizes.

Manufacturers of brass cladding also find the material to be extremely malleable and well-suited for decorative sheet metal work.

All are beautiful, and all have their own strengths and unique selling points.

If you are planning to use metal cladding on your project and you find it hard to choose, feel free to ask for your designer's input.There are many factors to consider when choosing a metal cladding: the weather conditions, configuration, structural systems, application, finishes, appearance, nature of adjacent materials, maintenance, and budget. Getting professional design and construction advice is the best way to go.