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Earthquake Mitigation for Homeowners

• Basic Preparedness
• What To Do During and After the Earthquake
• Mitigation Measures For Your Home
• Getting the Work Done
• Safety Outside The Home
• Other Resources

Steps to Prepare Yourself and Your Family for an Earthquake

Basic Preparedness

1. Store enough food, water and medical supplies for 3 days

• The following is an exerpt from an informational site from Humboldt State University in Northern Califonia:
  • “If a major earthquake knocked out your power, disrupted your water supply and damaged your home, could you cope on your own for three days? A major earthquake disaster would overwhelm local law enforcement, fire, and emergency medical personnel and resources. If transportation and communication channels are damaged, getting help may take hours or days. When a city cannot adequately meet demands for help, it requests assistance from neighboring cities and/or the county. If the county cannot adequately assist, the request is passed on to the State of Office of Emergency Services (OES). Finally, if state resources are insufficient, the Governor can ask the President to declare the county(ies) a Major Disaster Area and release federal assistance. This process may take days.”
• A complete list for a disaster supply kit is available from the Red Cross.

2. Prepare a home earthquake plan

• See American Red Cross’ Earthquake Safety Checklist for more information.

What To Do During And After the Earthquake

1. Know what to do during an earthquake
   The following is an exerpt from the Humboldt State University in Northern California:
   • If you are indoors, duck or drop down to the floor. Take cover under a sturdy desk, table or other furniture. Hold on to it and be prepared to move with it. Hold the position until the ground stops shaking and it is safe to move. Stay clear of windows, fireplaces, wood stoves, and heavy furniture or appliances. Stay inside. Outside, you may be injured by falling glass or building parts. If you are in a crowded area, take cover and stay where you are. Stay calm and encourage others to do likewise.
   • If you are outside, get into the open, away from buildings, power lines and trees.
   • If you are driving, stop if it is safe, but stay inside your car. Stay away from bridges, overpasses and tunnels. Move your car as far out of the normal traffic pattern as possible. Avoid stopping under trees, light posts, power lines or signs if possible.
   • If you are in a mountainous area, or near unstable slopes or cliffs, be alert for falling rock and other debris that could be loosened by the earthquake.

For a brief summary table about what to do during an earthquake, visit the the Pacific Northwest Seismograph Network site.

2. What to do after an earthquake:
   • If you are at the beach. Move to higher ground as soon as the shaking stops.
   • Check for injuries. Do not move a seriously injured person unless they are in immediate danger of further injuries.
   • Check for hazards:
     • Fire or fire hazards.
     • Gas leaks. Shut off the main gas valve only if a leak is suspected or identified by the odor of natural gas. Wait for the gas company to turn it back on once the damage is repaired.
     • Damaged electrical wiring. Shut off power at the control box.
     • Downed or damaged utility lines. Stay away from downed lines, even if power appears to be off.
     • Fallen objects in closets and cupboards. Displaced objects may fall when you open the door.
     • Downed or damaged chimneys. Approach chimneys with caution. They may be weakened and could topple during an aftershock.
     • Your telephone. Make sure each phone is on its receiver. Telephones off the hook tie up the telephone network. Use only in the event of a lift-threatening emergency
     • Clean up. Potentially harmful materials and/or medicines may have spilled.
     • Expect aftershocks. Most of these are smaller than the main earthquake. Some may be large enough to do additional damage to weakened structures.
     • Listen to the radio. Radios are your best source of damage reports and other information. Search the radio dial for Emergency Broadcast Stations near you which are on the air and able to give information.
     • Anticipate tsunamis. To learn more about tsunami risks, visit our tsunami page.

   For a brief summary table about what to do after an earthquake, visit the the Pacific Northwest Seismograph Network site.

Mitigation Measures For Your Home

Protect Your Belongings

• Move heavy items, such as pictures, mirrors or tall dressers, away from your bed.
• Secure tall furniture and bookcases with lag bolts to wall studs. Add lips to shelves to prevent costly items from sliding off their supports.
• Put latches on cabinet doors, especially at home in your kitchen and at work or in school laboratories.
• Fasten heavy or precious items to shelves or tables. Secure file cabinets, computers, televisions and machinery that may move during an earthquake. Use easy tack putty to secure fragile objects on shelves.
• Store potentially hazardous materials such as cleaners, fertilizers, chemicals, and petroleum products in appropriate containers and in sturdy cabinets fastened to the wall or floor.
• Fasten heavy objects to the building structure and not just to a movable wall in your office. Ask a carpenter or an electrician to determine whether light fixtures and modular ceiling systems are securely fastened.
• Be sure your water heater is fastened to the wall studs and that all gas heaters and appliances are connected to the gas pipe through flexible tubing (Figure 1). If you use propane gas, be sure the storage tank is secured (Figure 2).
• Secure your wood stove to wall or floor studs (Figure 3). Make sure you have a fire extinguisher close at hand.

Directions to Secure Your Water Heater, Wood Stove and Propane Tanks

• Figure 1. Securing your water heater:
  • Wrap a 1-1/2-inch-wide, 16-gauge-thick metal strap (A) around the top of the water heater and bolt the ends together.
  • Do the same about 1/3 of the way up the side of the water heater. Take four lengths of EMT electrical conduit, each no longer than 30 inches. Flatten the ends. Bolt one end to the metal strap as shown (B).
  • Screw the other end to a 2-inch by 4-inch stud in the wall using a 5/16-inch by 3-inch lag screw. Be sure a flexible pipe (C) is used to contact the gas supply to the heater.
• (source: California Office of Emergency Services )

• Figure 2 – Anchoring Your Stove
  • For stove on a brick hearth, anchor stove with 3/8-inch diameter bolt (A) through 1/2-inch hole to new brick (B).
  • Grout brick to existing hearth with 1-inch new grout (C).
  • Alternatively, build 8-inch square brick pad with grout pocket (D) at each leg. Provide at least 1-inch grout all around leg, fill pocket completely with grout.
  • Provide sheet metal screws (E) at flue exit and between stovepipe sections.
  • Provide radiation shield with pipe clamp (F) braced to wall using two Simpson WTT187 tension ties or equivalent (G) attached to wall stud with 3/8-inch by 3-inch lag screws
• (source: California Office of Emergency Services )

• Figure 3. Propane Tank Anchorage.
  • Mount tank on 6-inch thick concrete pad (A) using four 1/2 diameter bolts (B) with 3-inch minimum embedment into the concrete.
  • Provide a flexible hose connection (C) between the tank and the rigid supply line.
• (source: California Office of Emergency Services )

Getting The Work Done

How do you locate professionals to advise you on the resistance of your building to earthquake shaking? Who should perform the needed construction? Civil and structural engineers and architects are trained to provide such information about structures. Geologists, foundation engineers and geotechnical engineers are trained and licensed to evaluate soil conditions and recommend appropriate action. A contractor has to implement the detailed plans and specifications prepared by an architect or engineer.

A good place to start is to call a professional organization and ask about the types of work that might be required; how to select an engineer, geologist, or architect; and a list of members in your area.Contact several firms or individuals to determine whether they do the types of work you need. Make sure the firm has the necessary licenses and has experience in strengthening structures to resist earthquake shaking. Check to see how satisfied other clients were. Recognize that the quality of the advice given and the work performed, as well as the price you pay, may depend on the care you take in making your selection.

Become informed. Even if you do not understand the technical details, ask enough questions to understand the concepts and relative importance of the issues involved. You have a right to understand what needs to be done and why.

State and federal agencies do not inspect individual buildings. Your local building department may be willing to inspect your building, but they are not authorized to recommend actions to be taken.

Information for this section has been taken from Humboldt State University’s on-line publication: Living on Shaky Ground: How to Survive Earthquakes and Tsunamis on the North Coast of California.

Safety Outside The Home

Although much of our time is spent in the home, a considerable portion is spent outside the home. Some earthquake related questions that you might want to ask are:

• Is my workplace retrofitted for earthquakes?
• Does my workplace have an training program or plan so that employees know what to do in case of an earthquake?
• Is my child’s kindergarten, school or daycare facility retrofitted for an earthquake, and are the care providers trained for an earthquake eventuality?

Other Resources

Information about the Homeowner’s Guide to Earthquake Safety from the California Seismic Safety Commission is available on-line.