House earthquake retrofitting for foundations, chimneys, gasoline


1. Foundations: The most common type of home found in Southern California prior to 1980 is an elevated foundation. These have either front or crawl space walls, both of which require foundation anchor bolts to secure the frame to the concrete. If your home has crawl space walls, you may also need to add plywood bracing to the interior walls.

The Standard plan set 1 and the FEMA P-1100 are ready-made plans that enable efficient retrofitting.

Of all the retrofits his company performs, 30 to 40% of jobs follow Standard Plan Approach 1, according to Whallett.

Since it is the most common type of retrofitting, it takes the least time and is the cheapest. All work is done under the house so that daily life is minimally disrupted. Other types of homes may take more time – and more money. While we have shown a house with an elevated foundation here, you may have different needs depending on how your home was built.

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In the San Francisco Bay Area, residential quarters above garages are common. To prevent a house from crumpling, the walls of the garage should be reinforced with plywood and a steel frame should be installed around the garage door. Proper retrofitting costs $ 10,000 to $ 15,000, according to the California Residential Mitigation Program.

Hillside homes, like those found in the canyons and slopes of LA, take a lot more time and effort. These modifications require an engineer’s eye, and it is recommended that you do not attempt these renovations yourself. Because of the complexity, retrofitting could cost around $ 10,000.

Homes with an area below the main living area are not common in Southern California, but they are particularly prone to slipping as they do not have a continuous concrete foundation. Retrofitting for this type of home is more complicated and requires both an engineer and a licensed contractor. A complete upgrade can cost up to $ 15,000.

Seismic retrofitting is the bare minimum that you can do to keep you and your home safe. You should also consider the following:

2. Gas: Installing an automatic natural gas shut-off valve in your gas line can help prevent leaks and potential fires after an earthquake.

3. Chimneys: They’re calming and nostalgic, but brick chimneys are a huge safety hazard, Maffei said. It used to be recommended that the chimney be braced against the house, but Maffei said it was best now to demolish and rebuild.

4. Water Heater: Securing your water heater to wall studs is another simple solution you can do yourself to reduce the risk of water damage, gas leaks, and fires. Replacing water and gas lines leading to the heater with flexible options is also recommended by the Earthquake Country Alliance.

Here are links where you can research further: