Info on Chimney Safety and Earthquakes

Chimney safety should be a high priority.

In the 1994 Northridge earthquake, approximately 60,000 masonry chimneys were destroyed or damaged beyond repair. Most chimneys tend to break at the roofline and fall away from the home. However, some chimneys can fall into the home, causing serious injury and death.

 

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The California Seismic Safety Commission Guide states: "Tell your family members to get away from chimneys and fireplaces during earthquakes." Thus, don't use the area outside next to your chimney as a play area for your children. In addition, don't use the area inside next to your chimney as a sleeping area! The one fatality in the 1992 Landers earthquake was a child sleeping next to a fireplace and the one near fatality in the 2000 Napa earthquake was a child that was having a birthday party sleep-over next to the fireplace.

You can put sheets of plywood above the ceiling framing to reduce the chance of bricks falling through a sheetrock ceiling. Retrofitting masonry chimneys with bracing or strapping is not an effective safety measure because many braced or strapped masonry chimneys typically will still fall when exposed to violent shaking.

If you are more concerned, you can consider replacing your masonry chimney with a modern stud-framed one around a metal flue, not simply bracing or strapping it. Generally, the cost of replacing an existing brick chimney with a lightweight one is comparable to the cost of repairing or replacing a damaged chimney after an earthquake. Another option is a partial chimney replacement in which all of the bricks above the firebox are removed. The upper portion is then replaced by a stud-framed chimney and a metal flue. This partial replacement has been used to repair chimney damage after earthquakes and removes most of the potential life-safety problem. For example, this partial replacement technique is used by the City of Los Angeles. Click on the following for a LINK to the City of Los Angeles 17-page Adobe Acrobat (PDF) report on the procedure.


ABAG, the Association of Bay Area Governments, is the regional planning and services agency for the nine-county San Francisco Bay Area.

This page was last updated 8/10/04 by jbp.