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Materials that Resist: Non-combustible Metal Plate

La Raza
National Council of LaRaza, Washington, D.C.

Over time, building exterior envelopes have become more intricate. To enhance the performance of a building, more insulation is needed, for example, in addition to any of the stylistic elements and functional considerations like rainscreens, an article in The Code Corner noted. What’s more, is that there are simply more materials on the market from which architects and designers can choose to create a building that is more interesting, functions well, and allows them to exercise their aesthetic visions. These materials are then combined to meet building code requirements, ensure the structure and its performance statistics adhere to environmentally friendly standards and still create something that has visual appeal.

A functional, attractive building must also be safe, particularly from the threat of fire. Materials defined as noncombustible must test in accordance with ASTM E136, “Standard Test Method for the Behavior of Materials in a Vertical Tube Furnace at 750°C.” Alternatively, if a wall system design calls for an item or component in the wall assembly that is considered “combustible,” then that assembly needs to be tested to assess fire performance in the as-planned conditions.

When different materials are combined to form the building envelope, it is imperative that they pass NFPA 285, which measures the “suitability of exterior, non-load bearing wall assemblies and panels used as components of curtain wall assemblies that are constructed using combustible materials or that incorporate combustible components for installation on buildings where the exterior walls are required to be non-combustible,” according to the official standard.

Testing often takes place in a controlled environment, and the NFPA has introduced a free assessment tool where authorities—with jurisdiction—can measure the safety properties of a building believed to include combustible materials. It is a way to assess risk across a portfolio of buildings so action can be taken on those considered to be high risk, and can also indicate where a structure may need a more in-depth assessment from qualified engineers.

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With the range of materials on the market, architects certainly have many options from which to choose. Some building products are more fire-resistant than others. If metal is the desired material for new construction—or to refurbish a current structure—solid metal plate is considered to be the ideal material.

Metal plate is a robust, viable and aesthetically versatile material. This cladding material offers superior strength and formability with design possibilities, performance, lightweight composition, strength, finishes and durability. Products and systems produced from this material can be used as architectural features, or as exterior or interior cladding products.

To be considered solid metal plate, the metal must be at least 1/8-inch thick, delivering not only an extremely flat, but durable surface. Other lighter gauge materials can offer similar properties, but those products are considered formed metal and are not necessarily plate as understood by the metal producer. Those thinner metal formats are perfectly suitable for smaller module panels. However, for large format panels, exceeding 36-inch modules, a plate substrate is more suitable for the most stable, strong, impact resistance and non-combustibilty.

With a melting point of over 1200 F (aluminum), solid metal plate is non-combustible, so fire safety issues are never a concern. There are no plastic or foamed components required, which renders NFPA 285 testing protocols inapplicable. In addition, solid metal plate does not contain toxic or flammable plastic additives.

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Other metal façade systems may be comprised of either polyethylene or polymeric cores, which will begin to lose their structure sooner, at much lower temperatures. The risk increases when they are used in high-rise buildings; according to Fire Engineering magazine, some of these products are made inexpensively and utilized where structures need to be raised quickly, as is the case for housing in some parts of the world. The core is what differentiates this kind of system from metal plate. Because the inner layer is made, essentially, from plastic, it needs to be of a high quality with a polyethylene/mineral fiber core to be fire rated. Otherwise, it will melt and a fire will be able to spread more quickly.

Metal plate presents a worthy alternative material and it also has a strong aesthetic appeal. When properly designed and engineered for project loads, solid metal plate offers the highest level of longterm performance. Most notably, it has a low risk of damage or denting during installation and the highest degree of durability compared to other sheet metal or composite metal products. Its systems are produced from homogeneous materials, meaning they are never fused with foamed or plastic cores. Therefore, there is no concern for delamination or the separation of layers. In addition to its longevity, the amount of maintenance plate requires is very minimal.

The design and construction community expects more from buildings than ever before. Finding the right solutions is key to producing structures that perform well, keep users safe and look appealing. Metal plate is one way to help mitigate the issue of fire safety while ensuring that the structure is sound and visually appealing for years to come.


Stephen J. Scharr, Esq., is a business development professional with Metalwërks, Kennett Square, Pa. He was president of Metalwërks for more than 20 years. Scharr is also a licensed attorney specializing in construction-related issues. He has provided legal liability and contract consulting services for manufacturers and specialty contractors. In 2014, Scharr co-authored a section of the book, “Construction Subcontracting: A Comprehensive Practical and Legal Guide,” published by the American Bar Association (ABA). Scharr is a member of ABA’s construction forum and the Pennsylvania Bar Association. He can be reached at e-mail at stevescharr@metalwerksusa.com.