How to Prepare Your House for an Earthquake
- In This Quick Guide:
- Bolts, Straps, and Retrofits
- Quakeproofing Your Utilities
- High-Tech Home Tech
Of all natural disasters, earthquakes are probably the least understood and the most feared. There’s still no reliable way to predict them, but with the prevention techniques in this guide you can be ready for when they do strike.
Bolts, Straps, and Retrofits
One of the most common problems for older houses is that the structure jumps or slides sideways and skates off its foundation. You can have the house attached with special connectors to the foundation to prevent this.
The foundation itself may also need reinforcing: for example, an old pillar and post foundation could fall sideways in an extended earthquake that got the house swaying back and forth. Additional supports and braces may be required. Chimneys, particularly those that are much higher than the roofline, can crumble and fall through the roof. You can add reinforcing and support, or you may even want to replace the entire chimney with lighter, stronger insulated pipe.
Foundation and structural work is expensive, but if you’re in an earthquake zone, it could be worth it. (Sometimes it can result in a reduction of earthquake insurance rates, too.) If your house falls off the foundation, it’s probably going to be a write-off. Remember, though, that retrofitting and even completely earthquake-proof new construction isn’t proof against any quake. It just means that you’re most likely to survive an earthquake with as little structural damage as practical.
Of more immediate concern is what’s happening inside. Quakes big enough to shake your house off its foundation are thankfully rare. Quakes that can knock things off shelves are far more common, and it’s this type of damage that you have to prepare for. A 5.4 quake can, for example, do any or all the following:
- Open cupboard doors and throw coffee cups or plates on the floor.
- Throw books off shelves.
- Knock paintings off the wall.
- Tilt entire bookshelves over.
- Move the refrigerator out 3 feet.
- Drop a ceiling-mounted light fixture to the floor.
- Shake a TV out of an entertainment center or wall niche.
- Swing a hanging plant or wind chimes into a window.
Look around your house and see where there are large or heavy objects that can fall over (such as bookshelves) or fall down (such as a painting). The first thing to do is put earthquake strapping on anything that can fall over. For bookcases, grandfather clocks, and refrigerators, this is usually nothing more than a piece of heavy woven fabric band and a couple of screws to anchor it in the back of the object and the wall. You don’t need something that can bear the weight of the object falling forward; you just need enough to stop it when it rocks out a few inches.
Statues, souvenirs, and other knickknacks on shelves and mantles can be held in place with museum putty or gel. These are neutral adhesives that hold items in place so they can’t be shaken loose. Consider adding a monofilament line an inch or two, held in place with thumbtacks or a little tape, above each shelf to keep objects from bouncing off the edge.
Paintings and hanging mirrors can be secured with heavier hooks, a second wire (as a backup in case the first one breaks free when shaking), or corner brackets that anchor the frame securely and prevent it from swinging.
Other things to make your house a little safer:
- Move heavier items to lower shelves.
- Install latches on cupboards.
- Keep cleaning supplies, flammables, and other chemicals where they can’t fall and break open.
- Check overhead fixtures and hangers.
- Add a monofilament guy line to hanging plants or wind chimes so they can’t swing into anything breakable.
Quakeproofing Your Utilities
Your utilities need to be quakeproofed, too. Start by checking your wiring, gas lines, and plumbing. If you have frayed lines or weak joints, replace them. The jerking motion of a quake can tear electrical lines and rupture gas lines, causing fires, and crack water lines, causing flooding.
If you use gas, check with your gas company about getting an earthquake shutoff valve. The most common of these is basically a valve with a large ball sitting on a post inside it. If the ground shakes, the ball is knocked off the post into the pipe below, blocking the gas flow. There are also gas and water “leak cut-off” valves that detect broken pipes based on pressure changes or on water accumulation. There are even seismically activated electricity shutoff valves, too.
There are special strapping kits for your hot water heater that bolt into the wall. They take about an hour to install. Even if the chances of an earthquake in your area are low, put one in just in case. You should also strap any other gas appliances in place so they dont “walk” out from the wall and break open the gas connection.
High-Tech Home Tech
Many new building materials are designed for earthquake safety. Although these are more applicable to new construction, some of them are designed to be put on as part of a quakeproofing remodel or retrofit.
One of the simplest techniques is to install windows that have the glass panes not touching the corners of the frame. This lets the glass move slightly in the frame during a quake rather than crack and then shatter because it’s pushed into the glass frame. Rounding and polishing the corners of the panes makes the windows significantly less likely to break.
Another quake retrofit is to add security films to windows. These won’t prevent the glass from shattering, but will prevent shards of glass from covering an area.
Your best defense against earthquakes is to be prepared. Making these adjustments to your home will not only save your home and your your valuables, it will give you peace of mind. Good luck!
From The Complete Idiot’s Guide to Disaster Preparedness by Dr. Maurice A. Ramirez, DO, and John Hedtke
