Larger imageThis building sustained extensive interior nonstructural damage during the 1994 Northridge earthquake. Parts of the ceiling grid and tiles have fallen.

Source: Wiss, Janney, and Elstner Associates

The Problem

Unbraced acoustic-tile ceiling systems can shake loose during earthquakes. Heavy light fixtures and duct vents are particularly hazardous to occupants if they are not properly connected to the roof or the floor above (see drawings below). Unbraced ceilings can hit fire sprinkler heads, which may release water and flood the building.

How to Identify It

Lift a ceiling tile and look up into the space above the ceiling. If the tiles seem loose in their frames, they may fall when the building begins to move. In rooms more than 12 feet wide, you should see diagonal wires and vertical pipe struts connecting the ceiling tiles' framework to the building's framing above, spaced every 12 feet.

Look for wide, secure supports for the ceiling framework around the room's edges.

Each light fixture and duct vent should be securely supported with at least two wires to the building framing above.

What Can Be Done

Wire hangers and braces can be added to ceiling systems, light fixtures, sprinklers, and vents. You can either make the additions yourself or hire a contractor (see "ceiling" pages for more details and information).

Make sure there are gaps that will allow pipes to move where they pass through ceilings and partitions.

Larger imageBracing ceilings - This view from the top of the ceiling tiles shows diagonal bracing and struts to keep the tiles from falling in earthquakes.

Source: California Office of Emergency Services

Larger imageLighting fixtures - Fluorescent lighting fixtures should be secured so they will not present hazards.

Source: California Office of Emergency Services