Before the Quake
First tackle general preparedness. Emergency plans, supplies, and information sources will be critical for coping with any emergency. Next, it's time to tackle getting ready for specific types of emergencies. Review insurance coverage. Be sure to check not only the amounts of coverage, but what is covered. Coverage for earthquakes, floods, or sewage backup for example, requires either separate policies or riders on an existing policy. Now is definitely the time to find out.
There are two main areas to consider in making your home or business "earthquake ready":
- Nonstructural hazards: Nonstructural refers to your home's contents and parts of the home that do not actually hold the structure up, such as light fixtures, ducts, utility pipes, wiring, drop ceilings, decorative interior and exterior finishings, chimneys, cabinets, etc. Some nonstructural hazards can be eliminated simply by rearranging furniture or cabinet storage. Many could be done as a homeowner's do-it-yourself project with minimal expense.
- Structural integrity: Identifying and eliminating structural hazards (retrofitting) usually involves contracting professionals.
Nonstructural Hazards and Solutions
Do not underestimate the importance of reducing nonstructural hazards. Unsecured building contents such as toppling bookcases injure and kill during earthquakes. Billions of dollars are also lost due to this type of damage. Much of this could be prevented by taking simple, inexpensive steps ahead of time. More and more hardware stores and home centers carry earthquake safety straps, fasteners, and adhesives for home hazard reduction projects.
Look for potential hazards throughout your living and storage spaces. A good rule to follow is to secure or relocate items that are:
- Heavy enough to cause injury if it falls on you
- Fragile and/or expensive enough to be a significant loss if it falls
- Move heavy objects to lower shelves.
- Use latches to secure kitchen cabinets and drawers. Child-proof latches, hook and eye latches, or positive catch latches designed for boats can also work for quake-proofing.
- Store breakable items such as bottled foods, glass, and china in low or closed cabinets with latches.
- Secure refrigerators and other major appliances to walls using earthquake appliance straps.
- Fasten shelves securely to walls. Movable shelf inserts can also be secured by applying earthquake putty on each corner bracket.
- Keep tall, heavy items such as bookcases away from beds and couches and sitting or sleeping areas. Heavy pictures, mirrors, etc, should not be hung over places where people sit or sleep.
- For tabletop or display items on shelves, use either hook and loop fasteners on the table and object, or non-damaging adhesives such as earthquake putty, clear quake gel, or microcrystalline wax to secure breakables in place.
- Mirrors, framed pictures, and other objects should be hung from closed hooks so that they can't bounce off the walls. Pictures and mirrors can also be secured at their corners with earthquake putty. Only soft art such as tapestries should be placed over beds or sofas.
- Televisions, stereos, computers, microwaves and other heavy and costly to replace electronics can be secured with flexible nylon straps and buckles for easy removal and relocation.
- Secure the tops of all top-heavy furniture, such as bookcases and file cabinets, to a wall. Be sure to anchor to the stud, and not just to the drywall. Flexible fasteners such as nylon straps allow tall objects to sway without falling over, reducing the strain on the studs.
- Move flammable or hazardous materials to lower shelves or the floor.
Basements, Garages & Storage Spaces
- Have a plumber install flexible (corrugated) copper water connectors, if not already done.
- Store hazardous or flammable materials (cleansers, solvents, weed killers, pesticides, etc.) securely in sealed containers, on bottom shelves inside closed cabinets with latches.
- Keep an adjustable wrench near the gas shut-off valve, or attach it in an easily accessible location. Show everyone in your household where it is and how to use it.
- Automatic gas shut-off valves are also available. They must be installed by a qualified plumber. It senses an earthquake of magnitude 5.3 or greater. The drawback to such valves is they also may shut off when a heavy truck passes. The advantage is that a potential fire hazard can be eliminated, even if no one is at home when a quake occurs.
- Brace overhead light fixtures.
- Repair defective electrical wiring and leaky gas connections. These are potential fire risks.
- Secure a water heater with straps that are bolted to wall studs or masonry. Unsecured water heaters often fall over, rupturing rigid water and gas connections, leading to additional damage and risk of fire.
- Install flexible connectors on gas appliances to reduce the risk of fire.
View additional information, including how-to instructions, at the Earthquake County Alliance website.
Retrofitting Your Home
Retrofitting homes can be a significant commitment of time, effort, and expense. Experts advise homeowners to consider carefully what they are getting into before taking on a do-it-yourself retrofitting project. Tools and equipment are expensive, even if renting. Licensed contractors can also be a significant expense. On the other hand, the investment in retrofitting versus the cost of major repair or reconstruction can pay off many times over.
Structural Integrity Potential Problem Areas
- Foundations: Check for cracks, crumbling and evidence of standing water. Check the type of foundation and whether the structure is securely attached to it.
- Cripple Walls: Cripple walls are the short walls between the foundation and the first floor. During an earthquake, cripple walls can act like hinges, allowing the house to shift off its foundation, which can rupture utility lines and damage the entire house. Reinforcement with plywood sheathing (called shear walling) is recommended as a preventive measure. Shear walling is also recommended at the ground floor for 2- and 3-story homes.
- Garages: For homes with garages below the living spaces, steel reinforcement or added shear walling can help prevent structural buckling that is commonly caused by earthquakes.
- Chimneys: More than 10,000 chimneys were destroyed during the Loma Prieta earthquake in 1989. Falling chimney bricks can cause injury or serious damage, including actually penetrating through the roof. The degree of vulnerability depends on the chimney's age, location, height and the condition of the mortar. Chimneys extending 5 feet or more above the roof are the highest risk. Consult a qualified contractor or engineer about your chimney's condition.
- Masonry Veneer: Stone, brick and adobe are sometimes used around fireplaces or on the exterior of houses. Older veneers are especially vulnerable to earthquake damage, and not much can be done to reinforce them. Like falling brick, falling stone or masonry veneer can be extremely hazardous.