The Metal Construction Association (MCA) has published a new white paper, “Allowable Deflection for MCM Cladding – Why L/60?”

This paper details the benefits and limitations of Metal Composite Material (MCM) in regard to deflection. MCM is known for the ability to deflect and return to the original orientation once the loading is removed. Even so, the MCM manufacturer should test for the point at which the panel yields and there is permanent deformation.

There are many structural calculation methods/programs available today to determine panel stress and deflection. The use of L/60 has been shown to be acceptable for formed metal sheets, as well as in compliance with the International Building Code (IBC). The paper discusses the use of stiffeners to meet these deflection requirements, as well as their potential drawbacks.

“Designers and specifiers of MCM will benefit greatly from the data and insights this paper offers,” says Tom Seitz, chair of MCA’s MCM Alliance, “While many are experienced with the challenges of panel deflection and minimizing the visual impact associated with the use of stiffeners, this paper can help them identify the best solutions for multiple panel challenges and why MCM is an excellent option.”