Seismic Design for Ceilings

We may not be a high risk area for earthquakes, but they do happen. In the 1980s, an earthquake centered in Albany, NY measuring 3.8 on the Richter Scale was felt by more than 12 states, including Connecticut.

Richard Ferarra, of USG (United States Gypsum Company) shared his knowledge of how to best secure ceiling tile in a quake. The goals are to avoid twisting of the steel and to keep ceilings from falling in. He stressed that, "To achieve this you hold the system together while allowing for movement."

To keep the system together it is important to use seismic clips which are rated for the risk area you are in. These clips provide:

• rigidity
• connection strength
• system tightness

It is important to include specifications in construction documents which provide a system to reduce damages that could be caused in the event of an earthquake. Appropriate systems for each risk area will include such things as weight of grid, appropriate clearances (to allow for movement), clips, wires (NY requires rods in lieu of wire), compression posts (to help with wind), etc.