It could hardly be considered surprising that metal cladding is becoming increasingly popular in modern architecture. It has a place in a wide range of projects from agricultural buildings, to individual homes, to large scale commercial construction. This versatility of use is due to the wide variety of materials, colors, shapes, and designs that can be achieved with metal cladding.
For a modern architect planning their next project, this range of choice begs the question: of all the options available, which is best for me and my goals?
When it comes to metal cladding, nearly every project will use one of four options: stainless steel, aluminum, zinc, or copper. While there are other choices available (including an alloy of two of those metals), most projects will opt for one of the four. This article will examine each of these architectural metals and present the advantages, drawbacks, and key qualities of each material.
In a certain sense, stainless steel is the most low-end option compared to aluminum, zinc, or copper – it is the heaviest of the four metals, which puts practical limits on the amount of steel cladding a structure can support. Steel is also the least durable, needing to be replaced whole decades before copper or zinc cladding would need the same.
Despite having several drawbacks, steel is still a highly viable and flexible choice. Steel is almost always the cheapest metal in terms of upfront material costs, and although it is less durable, it will still last 35 to 40 years (depending on the coating of the steel) before needing replacement. Although steel is the only of the four metals naturally vulnerable to rust and corrosion, it achieves a multi-decade lifespan with a protective outer layer, typically either hot-dip galvanization with zinc or zinc-aluminum alloy or a polymer lacquer. This outer treatment has the added benefit of providing a range of color choices.
Aluminum is the main competitor to steel since it’s also an inexpensive material relative to high-end metals like copper or zinc. In addition to being cost effective, aluminum is the most lightweight of the four materials, offering obvious benefits in terms of minimizing the total load on structures and potentially limiting the outlay on foundations. This relative lightness also makes aluminum very easy to bend and work on site, making it especially well suited to unusual, innovative, and futuristic cladding schemes.
Aluminum is comparable to steel in terms of its durability, lasting for around 40 years based on the coating used, and can be produced in a variety of colors and textures based on the artificial coating it’s treated with, allowing for highly defined and lasting patterns not achievable with other metals.
Lastly aluminum has a high expansion coefficient, meaning that it will contract and expand noticeably based on the surrounding temperature, which must be considered before committing to using aluminum in construction.
Copper has a well-earned reputation as one of the most high-end premium architectural metals on the market. It’s aesthetically pleasing and is incredibly durable while still being comparatively light weight. Unlike aluminum and stainless steel, copper will naturally form a protective patina that protects it from corrosion and minor scratches. Newly installed copper will be the traditional reddish gold color, and, as it’s exposed to air, will transition over time through shades of brown before reaching the famous pale greenish-blue.
All of these attractive qualities do come with downsides however as copper is the most expensive of the four metals by a noticeable margin, making it difficult if not sometimes impossible to cover large surfaces on a budget. Copper’s value can also make it a target for potential theft by people looking to resell the metal as scrap.
While none of the metals on this list could strictly be called the “best” of the four options, there is a lot to like about zinc. Zinc shares many of copper’s most desirable traits – it naturally forms a protective patina that protects the metal from corrosion and light physical damage, allowing zinc cladding to endure a century with little or no maintenance. Zinc is also aesthetically pleasing, its stately grays and dark blues equally appropriate for ultra-modernism and the “historic” look associated with 18th century decorative architecture.
Like the other metals, aluminum, steel, and copper, zinc is highly workable, capable of being manufactured in a wide range of shapes, sizes, and textures, and can be used to cover the entire outer envelope of a building, even those with complex or avant-garde designs. Although zinc is more expensive than steel or aluminum, it is still a common enough material (the 24th most common on Earth) that it’s noticeably cheaper than copper, and is less at risk of being stolen than the more valuable material.
In light of all this, zinc’s current rise in popularity makes sense – it bridges the gap between high and low-end materials, offering the key benefits of a high-end metal like copper while still being more affordable.
Consult with Metal Experts Before Your Next Project
If you are considering metal cladding for your next architectural project, set up a consultation with the experts in the field – MetalTech Global. We are the largest stocking center of architectural zinc in North America, with facilities that allow us to process and reprocess zinc to order for our clients. Capable of producing custom sheets and coils of architectural metals for our clients, we’re known for high quality, expertise and quick shipping. Contact us today for a consultation on your next project.