USG Boral Seismic Ceiling Resource Center





USG Suspension Systems, Seismic FAQ's

How have the seismic codes changed in the last several years?

In the past, seismic force levels were considered in earthquake-prone locations detailed in NZS4203. Major revisions and an inclusion within the joint Standard AS/NZS1170 suite have changed the requirements, with more factors being taken into consideration than seismic installations in the past.

What is the basis for determining the seismic requirements for a suspended ceiling?

A number of factors must be taken into account: geographic location, soil condition, type of building, building importance type, occupancy, weight and height from the ground of the ceiling etc. An identical building in different zones will have different seismic restraint requirements, as will a ceiling at ground level compared to one 20 stories high.

Where can I find information about all of the installation requirements in a seismic ceiling?

USG BORAL provides detailed information on installation requirements, located under Literature/Resources

As a contractor or architect, what documents should I have to help me determine seismic requirements?

Currently, USG BORAL provides a comprehensive Generic Seismic Design technical brochure that will provide solutions for many common building types.  For projects that fall outside the scope of this document, a Seismic Guidelines brochure details the type of information required for a charted structural engineer with experience in suspended ceilings to calculate specific project design(s). These documents are based on the tested strength and technology specific to New Zealand manufactured USG DONN exposed grid ceilings and cannot be used for imported alternatives that may be offered for substitution.

Which suspension systems can I use in a seismic application?

All main Donn exposed grid suspension systems made in NZ including 24mm DONN DX and 15mm DONN Centricitee.

Which USG ceiling panels are seismic rated?

There are no seismic requirements for tile. However clipping of tiles in higher seismic prone areas will minimise likelihood of tile dropout.

Does USG BORAL have a clip that makes it possible to use 22mm wall angle

Yes, it is called ACM7.

Why is USG so active in seismic research?

USG has a long history of supporting the development and research of seismic ceiling design and application, and we remain committed to this endeavor through product development, participation in industry associations, and supporting the evolution of building codes as new knowledge and product technologies become available. In fact USG is the only manufacturer that continues to perform seismic qualification tests in the USA with both the University at Buffalo (SUNY), the Department of Civil, Structural and Environmental Engineering – Structural Engineering and Earthquake Simulation Laboratory (SEESL) as well as the University of California, Berkeley, Earthquake Engineering Research Center (EERC). We are proud to commit significant resources to this ongoing endeavor.

Locally, NZ manufactured grid is independently laboratory tested and result data used by global engineering company Sinclair Knight Merz to provide the basis for the Generic Seismic Design document.

Why do USG ceilings out-perform alternatives?

Since 1957 Donn suspension systems have set the standard, with the optimal combination of shape, size, steel gauge and connection details to produce the tightest systems available, with the greatest lateral and torsional stiffness. For these reasons, suspension systems from USG BORAL are proven to resist the lateral forces experienced in a seismic event, requiring less installation construction for a given ceiling.