As the Oct. 17 anniversary of the Loma Prieta earthquake approaches, I've been thinking about the particular seismic dangers posed by living in an Eichler home. All that glass, combined with unsecured post-and-beam construction on a slab foundation makes for a dodgy combination. This year is the Oct. 17 quake's 24th anniversary, significant because the new Bay Bridge eastern span, marked for retrofit after the quake, only just reopened.
So with memories of that disrupted Bay Bridge World Series still on the brain, I thought a little refresher on the basic tenets of Eichler earthquake safety would be in order.
Structurally retrofitting your Eichler can be a pretty invasive process (see Tanja Kern's comprehensive CA-Modern article on the subject). Some of the recommended upgrades, such as shear-wall bracing, are best carried out during a remodel, so when that time comes, do look into shear panels, upgraded ties, and roof diaphrams.
But there are a few easy steps every Eichler owner should take for basic earthquake safety that don't require more than an afternoon's worth of work.
Windows: This defining Eichler trait can be one of the most problematic when it comes to quakes. Stanford Eichler owner Hermine Horoupian, speaking to the Eichler Network a decade after the quake, recalled how her windows became deadly during Loma Prieta. "There was a tremendous noise and a tremendous force," she recalled. "Then all the glass at the same time just shot out of the windows. Big pieces of glass shooting across one end of the room to the other. Flying through the living room, and the dining room. It was really scary."
While a large-scale solution is to replace oeriginal single-pane windows with dual-pane safety glass, which crumbles instead of shattering (see our service directory for companies that can do this), the low-cost version is to simply coat them with safety film that will keep the shards in place (again, consult the service directory). This is a good idea anyway, to ensure against stray baseballs or dropped broom handles. While it is possible to install window film yourself, a professional will definitely do a better job.
Chimneys: Sadly there's no quick-and-easy way to retrofit a masonry chimney, and these can be quite dangerous, with falling bricks. If it makes sense to do so, a full or partial replacement with a stud-framed chimney around a metal flue can reduce that risk. Otherwise, the only thing to do is to make sure everybody in the house knows to evacuate the living room as soon as the trembling starts.
Water heaters: Beyond windows, one of the biggest safety threats during an earthquake is that of a toppling water heater, which can become a scalding missile and leave gas lines open. Fortunately, you can secure this yourself by bracing it against the wall. Kern suggested one basic method:
Mount metal straps around the top and bottom of your water heater and bolt the straps securely to the concrete wall or studs. Block in any gaps between the back of your water heater and the wall. Install an automatic gas shut-off valve at the gas meter, if it doesn't have one already, and know where your water shut-off is in case of emergency.
Another option, for those who don't have a conveniently located stud, or whose heaters are too far from the wall for the strap method, is to mount longer 2x4 blocks on the wall behind the heater, anchored to whatever studs are there. Then use rigid, heavy-duty shelving brackets on either side of the tank to hold plumber's strapping in place around it. You can see a diagram of this on disastersafety.org.
Earthquake kits: Finally, we all know we should have three days' worth of food, water, medical supplies, and other emergency wares on hand. There's nothing Eichler-specific about this, but if you don't have a kit, do yourself a favor and put one together using the tips on 72hours.org. If you do have one, it might be worth opening it up and just making sure everything's in order.
Stay safe out there, Eichler owners!