Simplifying seismic requirements

May 22, 2018

Suspended ceiling systems tested to meet all seismic design categories

Rockfon Tropic and Chicago Metallic Ultraline 4500 installed in Arkansas State University for seismic DEF requirements.

Arkansas State University HSS Building installed Rockfon products for seismic requirements.

Acoustic ceiling seismic requirements are complex. Helping simplify compliance with current building codes, we provide numerous Rockfon® Chicago Metallic™ ceiling suspension systems tested to ASTM C635 and ASTM E580, and capable of meeting all Seismic Design Categories (SDCs).

In the event of an earthquake, our seismic-rated ceiling systems help support life safety and the preservation of property. Combining grid with our seismic clips and separation joints creates a complete solution that not only performs as intended, but also helps reduce installation and inspection time, and saves associated material and labor costs.

Understanding code compliance and SDCs

A Seismic Design Category (SDC) must be established for each construction project, regardless of geography, according to the International Building Code (IBC). The IBC outlines six SDCs, A through F, ranging from the least to the most stringent.

SDC A, B, C, D, E, and F are based on:

  1. Anticipated ground motion
  2. Type of soil in a specific geographic area
  3. Occupancy category

Rockfon offers ceiling products to address all SDCs.

Meeting ceiling seismic requirements

Proper installation for seismic applications means that the suspended ceiling systems:

  • Must be strong enough to resist the lateral force imposed upon it without falling
  • Must prevent border panels from falling from the ceiling plane

Our exposed tee construction permits direct upward access to mechanical systems and is a cost-effective solution to seismic requirements. Stab-in cross tees cantilever during installation and will not fall out, making for an easier installation and protecting against lateral pullout. When utilized with the Chicago Metallic™ 1494 Seismic Separation Joint Clip, the clip sits on top of the grid members, hidden from view, maintaining sleek ceiling design in seismic installations.

Proving seismic performance

Chicago Metallic™ suspension systems are tested to ASTM E580/E580M “Standard Practice for Installation of Ceiling Systems for Acoustical Tile and Lay-in Panels in Areas Subject to Earthquake Ground Motions.”

Most of our intermediate-duty and heavy-duty systems perform as required per ASTM C635/C635M, “Standard Specification for Manufacture, Performance, and Testing of Metal Suspension Systems for Acoustical Tile and Lay-in Panel Ceilings.”

These products, including our Chicago Metallic® 1496 Seismic Perimeter ClipChicago Metallic® 1494 Seismic Separation Clip and Chicago Metallic® 1493 Unopposed Tee Clip, also have been tested successfully and rigorously at the Structural Engineering Earthquake Simulation Laboratory at the State University of New York at Buffalo.

Innovations and approvals

It is important to remember, while the building code establishes the minimum requirements, it is the code official who enforces its provisions. Code officials also have the power to allow materials and methods that are not prescribed by code but meet its intention.

When evaluating such innovations, code officials can perform their own analysis or they can rely on independent, qualified sources such as International Code Council-Evaluation Services (ICC-ES) to do the analysis and provide their findings

Rockfon products are listed under evaluation report “ICC-ESR 2631” as specific, technical evidence on which the code official can base approval of a particular design without delaying construction.

Contact us for personalized assistance in selecting and specifying a ceiling system to meet the seismic requirements of your next project.
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