Code-compliance, the S134 and MCM: Stepping through your most asked questions
Seeking versatility, sustainability, and variety, architects and designers have sought out architectural cladding materials that can help them create better, more beautiful buildings. Engineering innovations such as composite metal wall panels consistently rank at the top of the list of favorite building materials, with good reason. However, professionals across the construction industry rely on material manufacturers to help them navigate safety concerns.
“The building code can be intimidating,” says Michael Bowie, technical support specialist for ALPOLIC, a global leader in metal composite material manufacturing. “In particular, I get a lot of questions about fire safety. Our latest AIA CE presentation on building code fire requirements has been wildly popular. Many are just not familiar with the required testing that makes multi-story wall assemblies featuring composite cladding code-compliant.”
What is MCM?
Used on interiors and exteriors, skyscrapers and single-family homes, details, and entire building envelopes, this advanced cladding solution has been a favorite for design-build professionals the world over for the last 50 years. Metal composite materials (MCM) are most valued for their versatility. Easy to fabricate and install, available in nearly limitless colors and finishes, these innovative materials can make complex visions come to life.
Sustainable MCM is made from highly recyclable materials that support efforts in LEED certification. In as little as 1,000 square feet, affordable MCM can be produced to custom order with manageable lead times. With over 100 finishes in stock, these premium materials are ready to deliver exceptional results. Quality composite panels can come with finish warranties of 10, 20, or 30 years and deliver the look, performance, and longevity every building owner deserves.
The standard product features metal skins 0.5mm (0.02″) thick. Heavy-duty 0.8mm (0.32″) skins are also available. The finished product is offered in thicknesses of 3mm, 4mm, or 6mm, with 4mm being the architectural standard. Standard panel dimensions are 127cm or 157cm (50” or 62”) wide and 371cm or 498cm (146” or 196”) long, with custom sizes also available.
MCM is produced by bonding thin sheets of metal to either side of a thermoplastic core with heat and pressure. It provides the rigidity of plate metal without the weight or the distortion commonly referred to as oil-canning. Typically made with painted or treated aluminum, also known as ACM, MCM are also produced with zinc, copper, stainless steel and titanium, often referred to as natural metals. The thermoplastic core can be a traditional polyethylene (PE) or fire-resistant (FR).
What’s the difference between PE and FR core?
The different cores provide the same variety of attractive finishes, structural performance benefits and come in the same dimensions. Visually a glossy black, PE core is about two-thirds the weight of FR, often a lighter gray color. Both are rated under the CAN/ULC-S102 (Standard Method of Test for Surface Burning Characteristics of Building Materials and Assemblies). “PE has been used for decades, and is still the preference for many in applications like signage and quick-service restaurants, but only FR is used to pass testing required of buildings several stories in height,” says Bowie. FR material has been used as a component in a variety of wall assemblies that have successfully passed the CAN/ULC-S134 (Standard Method of Fire Test of Exterior Wall Assemblies). For this reason, FR core material is recommended when applied over 40 foot from grade.
What is the S134?
The CAN/ULC S134 is used to evaluate the fire performance and burning characteristics of an exterior wall with controlled fire exposure. The test measures the fire spread over the cladding, heat flow from a controlled fire to the exterior wall, and the fire spread within the wall assembly. The S134 is important for successfully building to the National Building Code (NBC) of Canada standards. Though it should not be considered a stand in for expected performance in all real-world fire conditions. Limited to the exterior wall alone, it does not evaluate framing details, the possible migration of fire to the interior wall, or the structural capacity of the exterior wall.
The S134, an independently certified test, provides an unbiased, standardized baseline for fire safety in Canadian cladding systems. The test wall assembly is 6 meters (19’8”) wide and 9.8 meters (32’2”) tall constructed over a concrete base, so only the exterior wall flame spread is visible. At the bottom of the test wall is a furnace that is used to simulate a fire exiting a window and climbing up a building. The focus is on flame spread and temperature, with heat flux measured using three sensors on the wall.
“Keep in mind, the test does evolve over the years,” notes Bowie. The ULC Standards are developed and published by this independent non-profit organization focused on all aspects of safety in Canada. Since the test came out decades ago, it has been reviewed and updated. Bowie recommends asking for a current S134.
“When you review the code, the NBC requires any MCM wall assembly systems to pass the S134. It’s part of the provision for exterior, non-load-bearing cladding systems that incorporate combustible components to be used in structures otherwise required to be of non-combustible construction,” explains Bowie.
How do you know if a material is non-combustible?
Defining what is non-combustible is a matter of setting the conditions under which flaming does not occur. In Canada, the NBC test for combustibility is CAN/ULC S114 (Standard Method of Test for Determination of Non-Combustibility in Building Materials). This test subjects a sample of the material to a specific heat, for a specific time and sets specific limits for flaming, mass loss and temperature rise. If the sample passes these conditions, that material is considered “non-combustible”. If the final product is a composite (such as MCM), all materials must be tested separately (core, skin and, if used, adhesive) and pass to be considered non-combustible.
If a material (or any of its components) does not meet the requirements of S114, then the NBC may set other criteria for a material’s use in non-combustible construction. For MCMs, those requirements are CAN/ULC S102 and, for multi-story applications, successful S134 testing.
Is your building material tested to the latest industry standard?
Build safety is critical for all facets of the design-build community. “Follow the code,” Bowie stresses matter-of-factly. When it comes to fire safety, the code is clear, and wall assembly tests such as the S134 support code compliance efforts for the Canadian market. “When you’re writing a spec or designing a wall, make sure your materials and wall assembly have up to date testing. Don’t accept anything less than strict code compliance.”
Note that in the United States, the International Building Code (IBC), has similar testing and standards for construction. The NFPA 285 is a full-scale wall assembly test, comparable to the S134. However, it is important to understand that these different national systems are not compatible with, nor interchangeable with, each other.
Still have questions?
The technical services department at your MCM manufacturer is ready to answer them. Navigating questions on specifications, like how do I choose the right installation system, or more project-specific questions, professionals like Bowie are ready to help. “Choosing the right material is a necessity for code-compliance and critical for safety,” Bowie explains. “Request the most up-to-date testing reports and ask questions. We want to help design-build professionals find the best solution for their needs.”
Industry experts like Bowie are just a phone call away. Manage tight lead times with responsive customer support, order free samples and literature for your design board, and reach out to the manufacturer’s technical service team to get reports like the Environmental Product Declaration (EPD), Product Transparency Declaration (PTD), and S134. Find a support team that is standing by for your toughest questions.
Building design comes with several design challenges and considerations. Of them, safety should always be top of mind. Build better with safe and beautiful metal composite materials that offer an adaptable, sustainable, and cost-effective solution. Exceptional projects demand exceptional materials. Design your next project with the help of premium ALPOLIC MCM. Request samples today.
Michael Bowie is the technical support specialist in the ALPOLIC Division of Mitsubishi Chemical America. After a decade of hands-on experience with the production and quality assurance of MCM, he stands ready to answer your technical questions. Learn more about how MCM can fit into your next project. Visit www.alpolic-americas.com or email [email protected].