Metal composite material (MCM)—as the name indicates, combines metal and plastic. It is simply a unified sheet good (or composite) made from two exterior metal skins bonded to a plastic core with a thickness of approximately 4 mm.
Understanding MCM’s many options and the key points in their system
This is a field-assembled system.
Physical properties like excellent strength-to-weight ratios, superior thermal stability and good impact resistance are just a few of the benefits that MCM can provide. Combine that with its fabrication capabilities (bending, curving, cutting and routing) and MCM provides an excellent base from which to design for those architects or contractors seeking to incorporate metal into their project.
Methods of Installation
To properly install MCM, it must be used with a system of aluminum attachment extrusions. These extrusions serve two basic purposes: 1) they allow the composite panel to be mechanically fastened to the building, and 2) they aesthetically address the joints between the panels—emphasizing or minimizing their appearance.
How these extrusions are configured will determine where the assembly of parts will take place. As a result, installation methods can be divided based upon whether they are shop-fabricated or field-assembled.
Shop-Fabricated
When budget allows and a minimalistic joint is desired, a fabricated system is often specified. This extrusion arrangement within a shop-fabricated system calls for all extrusions to be hidden. This is accomplished by routing flat sheet on the backside around the perimeter. Once the small flange has been folded back (or returned), the mounting extrusions are set inside the pan and attached. The pans are then hung upon another set of extrusions mounted to the building during the installation process.
Using this type of system allows the joint to be handled in a couple of ways. The joint between abutting panels can be sealed using a high-performance silicone creating a barrier system—preventing any moisture from entering the system. Or, if no silicone is preferred, the joint can be configured so that an accent panel is used and the entire system performs based upon the rainscreen principle. The factory-fabricated system offers the ultimate in high-tech appearance.
Field-Assembled
There is often the misconception that MCM is available only as a fully fabricated system of pre-engineered parts and assemblies. However, when the budget and/or time schedule does not allow for a shop-fabricated assembly, a field-assembled system may be specified.
There are several differences between the two types of systems, but perhaps the biggest is the perimeter extrusion. In the shop-fabricated system, the extrusion mounts to the return leg of the panel and is hidden behind it. In the field-assembled system, the extrusion captures the panel along the edge and is used to accent the joint (no routing or bending required).
The color-matched mounting extrusions are available in one or two-piece options, providing for a progressive or non-progressive installation. In addition, both flat profiles (used to create a monolithic look) and reveal profiles (used to simulate a fabricated system and accent the joint) are available within each type. The field-assembled system offers all the benefits of MCM in a package that installs faster, easier and in a more economical manner than factory fabricated systems.
Tips and Recommendations
Regardless of which type of system is specified, there are basic principles that installing contractors can use to enable the project to run much smoother:
• Know the sequence: since most MCM systems are progressive, fully understanding the order of steps and how they impact the elevations to be installed is critical.
• Layout the grid: in addition to using shop drawings and field measurements, it may be helpful to actually mark the grid on the substrate to discover any dimensional issues and/or penetration requirements.
• Plan spacing and intersections: know how the manufacturer’s joints are assembled and understand how each panel will interact with those around it, especially at complex corners or odd angles.
• Solidify substrate: no substrate is perfect but any steps that can be taken to clean up or flatten the surface prior to panel installation will benefit greatly.
• Move up and over: to take advantage of any scaffolding or lift equipment, work vertically first then horizontally across the elevation to reduce set-up time.
Understand the System and Your Options
MCM can be used in a variety of applications and installed in a number of ways. Knowing the options available, understanding the key points in the system design, and following a few basic principles will go a long way in making your next project one that fits both your design intent and your budget.
Sean Walker is the marketing manager at Citadel Architectural Products Inc., Indianapolis. For more information, visit www.citadelap.com.
This is a shop-fabricated system.
