Seismic Ceilings

Pont Consultants Ltd has been engaged by Ecoplus Systems to provide assistance with the preparation of a seismic design manual to ensure that installation of the FasTLock™ Suspended Ceiling Systems will meet the requirements of Clause B1 of the New Zealand Building Code with respect to seismic design.Testing of the ceiling grids and perimeter fixings was undertaken in 2013 by SGS New Zealand Ltd to determine compression and tension capacities. Appropriate reduction factors have been applied to determine the design capacity of the tees in accordance with section 8 of AS/NZS4600:2005, Section 8:Testing.

It is important that suspended ceilings are properly restrained against earthquake shaking. This is to reduce the risk of injury to people, cutting off exit routes from buildings and damage to property. The major Canterbury earthquakes of 2010 and 2011 highlighted how vulnerable suspended ceilings were to the forces induced from shaking during an earthquake. While some buildings suffered little damage to their structural systems, non-structural components such as ceilings were severely damaged.

Ceiling damage can be attributed to:

• Ceiling grid not perimeter fixed at one end or back braced.
• Ceiling grid tees being used with insufficient capacity under seismic tension or compression loads.
• Support structures or bulkheads with insufficient capacity to receive the seismic load from the ceiling grid.
• Differential movement of the main building structure.
• Engineering systems within the ceiling space not having independent seismic restraint.
• Partitions that are not independently braced.