Earthquake-Proofing Your Home

Furniture straps, gas shutoff valves, structural vulnerabilities — practical steps to secure your home before the next earthquake.

earthquake preparednessfurniture securinggas shutoffstructural safetyseismic retrofit

Preparation Reduces Earthquake Injury by More Than Half

Most injuries in earthquakes do not come from buildings collapsing. In well-constructed modern buildings, the primary injury mechanism is objects falling — bookshelves toppling, refrigerators sliding across kitchens, televisions launching off entertainment units, water heaters crashing through walls. These injuries are almost entirely preventable with basic preparation that costs very little and takes a weekend to complete.

The preparation measures described in this article are not for structural engineers. Most require no professional help — only basic hardware skills, a drill, and the right anchors. Where structural work is needed, specific indicators are provided.

Furniture Securing: What, Why, and How

Bookshelves and Tall Furniture

A fully loaded bookshelf can weigh 80–150 kg. During an earthquake, lateral acceleration causes it to rock and fall forward — directly toward whoever might be standing in the room. Children are at particular risk because they are at the height that a falling bookshelf strikes.

Securing method:

  1. Purchase L-brackets or anti-tip furniture straps (available at hardware stores, approximately $5–15 per unit)
  2. Locate wall studs behind the target wall — use a stud finder or knock along the wall listening for a solid sound
  3. Attach the strap or bracket to the rear of the top of the furniture piece
  4. Screw the other end directly into a wall stud — NOT into drywall alone, which will pull free under load
  5. If no stud aligns, use a toggle bolt rated for at least the weight of the furniture, or reposition the furniture

Water Heaters

Water heaters are heavy (50–100+ kg when full) and located near gas lines. An unsecured water heater that falls during an earthquake can rupture the gas connection, spilling flammable gas into the building — a primary cause of post-earthquake fires.

Code requirements: Many US states (particularly California) have legally required water heater strapping for decades. Even where not legally required, it is essential.

Strapping method:

  1. Use two metal pipe straps or a purpose-made water heater seismic strap kit (approximately $20–30)
  2. Upper strap at approximately two-thirds of the height of the tank
  3. Lower strap at approximately one-quarter of the height
  4. Both straps anchored to wall studs with appropriately rated lag screws
  5. Ensure the straps are tight and do not allow the tank to rock

Refrigerators

Large refrigerators on smooth floors can move significantly during an earthquake. If they shift toward a person, the result is crush injury. If they shift away from the wall, the water line or electrical connections can be damaged.

Use non-slip mats under the feet (anti-vibration pads) combined with a strap attached to the wall through the refrigerator cabinet to a stud.

Overhead and High Storage

Objects stored above head height in garages, workshops, and storage areas become projectiles during an earthquake. Apply this principle systematically:

  • Move heavy items to lower shelves
  • Store glass and breakables below waist height
  • Secure cabinet doors with child-safety latches that prevent swinging open
  • Store hazardous liquids (cleaners, paints, fuels) in low cabinets that are latched

Televisions and Electronics

Flat-screen TVs on stands are extremely vulnerable to tipping. Options:

  • Mount to wall using a proper TV wall mount (most effective)
  • Use anti-tip furniture straps from the rear of the TV stand to the wall
  • Place velcro anti-slip pads under tabletop items (decorative items, computer monitors, speakers)

Gas Shutoff: Location and Operation

Natural gas leaks combined with earthquake damage (broken electrical connections, shifted stoves, open gas appliances) is the combination that caused catastrophic post-earthquake fires in San Francisco (1906) and Kobe (1995).

Finding Your Gas Shutoff Valve

The main gas shutoff is located where the gas supply pipe enters your property. Typically:

  • On the exterior of the building near the gas meter
  • At the gas meter itself (a valve on the supply side of the meter)

If you cannot locate it, contact your gas utility — they will show you.

Keep the area around the shutoff clear. An accessible shutoff that is blocked by stored items is useless in an emergency.

Keep a shutoff tool available. Most gas meters use a quarter-turn valve that requires a crescent wrench or a dedicated gas shutoff tool (approximately $5) to operate. Tape the tool to the pipe near the meter.

How to Shut Off Gas

  1. Locate the valve on the supply pipe (before the meter)
  2. The valve is ON when the slot in the valve stem is aligned with the pipe
  3. Turn the valve 90 degrees (quarter turn) until the slot is perpendicular to the pipe — this closes the valve
  4. Confirm by attempting to light a stove burner — no gas should flow

⚠️ Only shut off your gas if you smell gas, hear gas hissing, suspect a leak, or see visible pipe damage. Do not shut off gas "just in case" — the utility company must restore gas service and relight all pilot lights. Unnecessary shutoffs during a wide-area event can leave you without gas for days or weeks while crews manage thousands of other properties.

Automatic Gas Shutoff Devices

Seismic-activated automatic gas shutoff devices detect ground shaking above a set threshold and close the gas supply automatically — before you even know the earthquake happened. They are:

  • Code-required in California for new construction and major renovations
  • Available for retrofit installation on existing gas meters (approximately $100–300 installed by a plumber)
  • Highly recommended for any property in a seismically active area

Structural Vulnerabilities: When to Be Concerned

Soft-Story Buildings

A "soft storey" is a floor in a multi-storey building that has significantly less lateral stiffness than the floors above and below it. The most common example is a residential apartment building with a ground-floor car park or open-ground-floor retail space — walls of glass and open space below, residential units with shear walls above.

In an earthquake, the soft storey acts as a hinge. The upper floors remain relatively intact while the soft storey collapses. Dozens of people have been killed in soft-storey collapses in earthquakes where better-constructed buildings nearby survived.

Identifying soft-storey risk:

  • Your building has large open areas on the ground floor (parking, retail, open piloti)
  • The building was constructed before 1980 in the US (pre-modern seismic codes)
  • You notice the first floor appears visually "lighter" and more open than upper floors

If you live in a soft-storey building, enquire with the building owner or local government about retrofit status. Many cities (Los Angeles, San Francisco, Seattle) have mandatory soft-storey retrofit ordinances.

Unreinforced Masonry (URM)

Brick, adobe, and concrete block buildings constructed without internal reinforcing steel are among the most dangerous structures in earthquakes. Mortar between bricks or blocks does not hold well under dynamic lateral forces. URM walls crack, separate, and can collapse outward — a hazard to occupants and to anyone outside the building.

Signs you may be in a URM building:

  • Older brick construction (pre-1950 in most US locations)
  • Visible brick exterior without visible steel or concrete elements
  • No earthquake retrofit or strengthening visible

Cripple Walls

Cripple walls are short wood-frame walls between the foundation and the first floor — common in homes built before 1940. They can collapse sideways during an earthquake, causing the entire house to drop off its foundation.

Retrofit: Plywood sheathing added to the interior of cripple walls provides dramatic improvement in resistance. This is a common DIY or low-cost contractor retrofit project.

Securing Your Garage

Garage doors span large openings. The wall area above the garage door is often understructured. During an earthquake, the portal frame of a garage can rack (distort sideways), damaging the garage structure and creating hazards.

Solutions include portal frame reinforcement kits designed for garage openings. A structural engineer can advise on the specific requirements for your garage configuration.

When to Hire an Engineer vs DIY

TaskDIY AppropriateEngineer Recommended
Furniture strappingYesNo
Water heater strappingYesNo
Gas shutoff tool installationYesNo
Automatic gas shutoff deviceNo (needs plumber)Optional
Cripple wall plywood sheathingYes, with permitConfirm design with engineer first
Soft-storey retrofitNoYes — complex engineering required
Foundation crack assessmentVisual inspection onlyEngineer for any significant cracking
URM wall reinforcementNoYes
Post-earthquake damage assessmentBasic visualEngineer for any structural concern

Foundation Types and Seismic Risk

Foundation TypeSeismic PerformanceNotes
Reinforced concrete slab on gradeGenerally goodCan crack in severe events; usually not life-threatening
Reinforced concrete perimeter + postsGood if properly constructedCheck for bolt connections between sill plate and foundation
Unreinforced concrete or masonryPoorHigh risk of failure in major events
Cripple wall on perimeter concreteModerate riskRetrofit with plywood significantly improves performance
Raised floor on wooden stumpsVariableStump connections and bracing critical

The connection between the building's wooden sill plate and the foundation is critical. Buildings bolt-connected to their foundations perform far better than those simply resting on the foundation (common in older construction).

Checking your connection: In your crawl space or basement, look along the sill plate (the lowest horizontal timber) for bolt heads passing through into the foundation. If you cannot find bolts, your building may not be anchored — consult a structural engineer.

Quick Reference

SituationAction
Bookshelf not securedInstall L-bracket or strap to wall stud — do today
Water heater not strappedInstall dual-strap kit; this is code in many areas
Heavy objects on high shelvesMove heavy items below waist height
Cannot find gas shutoffCall gas utility to show you the location now
Gas shutoff requires toolsTape a crescent wrench or shutoff key to the meter pipe
Smell gas after earthquakeDo not touch switches; leave building; call gas utility
Want automatic gas shutoffHave plumber install seismic-activated shutoff valve
Live in older brick buildingAsk building manager about URM retrofit status
Ground-floor parking under apartmentsAsk about soft-storey retrofit compliance
Older home on stumps with no cripple wallCheck for foundation bolts; consult engineer
Any structural crack in foundationContact licensed structural engineer for assessment
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