Metal is a highly durable material that is used extensively in construction because of its durability and strength. From steel frames to aluminium cladding, metal has an important role to play in modern buildings.
Non-ferrous metals are malleable, and they can be formed to make almost any design. Copper is often used in construction for its ductility and thermal and electrical conductivity. It is also sometimes allowed to oxidise to create a unique finish.
Steel
The most common framing material in the world today is steel. It is used in everything from high-rise buildings to kitchen appliances, and its tensile strength makes it ideal for building structures.
It is also highly cost-effective, especially compared to concrete alternatives. Steel building materials are frequently pre-fabricated off-site and delivered to the construction site ready for installation. This reduces labor costs and speeds up construction, giving a quicker return on investment for the project owner.
The primary raw material of steel is iron, which is mixed with carbon to create an alloy known as pig iron or steel. A wide range of other elements can be added to iron and carbon to produce different kinds of alloy steel for specific applications. These include chromium, manganese, tungsten, cobalt and molybdenum.
To create steel, the molten iron is poured into long rectangular forms called ingots. The ingots are then sent to semi-finishing mills (also known as slabbing or blooming mills) where they are reduced and shaped into slabs, blooms and billets.
The mechanical working of steel, such as rolling, forging and squeezing improves its qualities. It closes voids, disperses harmful concentrations of non-metallic impurities and refines the grain structure for more uniform products. Alloy steel is also extremely versatile and can be molded into the required shapes for different types of manufacturing.
Aluminum
The modern glass façades of skyscrapers literally rest on strong, lightweight aluminium frames. Often, they’re used in the same fashion for other large buildings such as stadiums and exhibition centres. The metal can be shaped and curved to accommodate unique designs and create different effects.
Unlike steel, which is not as malleable, aluminum is a ductile metal that can be reshaped to meet engineering design requirements. This allows builders to achieve more creative and useful elements in the construction of their projects. It also makes the structures easier to install and dismantle.
Another advantage of aluminum is its lower density. It weighs about a third of steel, which helps to reduce the overall weight of the structure without sacrificing strength. This can be helpful in reducing the cost of materials, as well as minimizing energy expenditure and maintenance costs.
Aluminium cladding offers an almost unlimited choice of colors and finishing options. It can be a solid color, like soft white or vibrant red, or it can feature textures, special finishes that alter their appearance under different lighting conditions, and even iridescent colours that change with the incidence of light. All of this adds to the visual appeal and sophistication of a building’s facade, resulting in a one-of-a-kind architectural masterpiece.
Copper
While not nearly as durable or strong as steel, copper is incredibly versatile. It is a key part of the plumbing systems in modern buildings and is widely used for electrical wiring. Copper is also a popular choice for roofing cladding. Its excellent conductivity and corrosion resistance offer a sustainable solution for building owners looking to create beautiful and energy-efficient structures.
While pure copper is a fairly soft metal, it can be made into a range of hard, ductile alloys that are ideal for specific uses. These include catenary wires for electric railways, and high-performance alloys with a combination of high conductivity and strength (for example, beryllium coppers). The tensile strengths achieved in these special types of copper mean that they can withstand significant stresses without failure.
For more than 100 years, steel was the standard frame material for bicycles – and it still is in many recreational applications today. However, in recent times, aluminium alloy frames have gained popularity with a number of major manufacturers switching to the lightweight material, especially for their pro-level racing bikes.
While aluminium is a durable, lightweight material, it does not resist corrosion as well as copper or stainless steel. This is why, when choosing materials for their construction, engineers need to consider the whole life cycle of a project, not just its initial cost.
Zinc
As the 24th most abundant element in the Earth’s crust, zinc is a naturally occurring material that provides an environmentally responsible choice for construction projects. Its availability offers economical pricing and a consistent supply for builders, while its malleability allows for easy shaping to fit specific design requirements, reducing waste from excess offcuts. Additionally, it’s a recyclable metal that requires fewer resources to produce than many other metals, decreasing energy consumption and carbon emissions.
Zinc is a popular choice for building facades because of its wide range of color options and unique texture effects, including a variety of metallic finishes. These eye-catching hues reflect light and add visual interest to the facade of a building. They also accentuate the colors of other building materials, such as wood and concrete.
Galvanized steel is a cost-effective construction material that lasts far longer than other common building materials. It is often used in the cold-formed steel framing that is standard for nonloadbearing partition walls in office buildings, but it is becoming increasingly favored for structural applications in mid-rise apartment and multifamily buildings as well.
In addition to its durability and strength, galvanized steel is corrosion resistant. A layer of protective zinc-iron alloy (called “galvanization”) prevents the base metal from reacting with oxygen in air to form rust. This feature explains why the majority of cars on the road today use galvanized steel for their body-in-white, with some companies offering rust warranties to customers.