Is your home safe in an earthquake?
If you are moving to California, or have recently arrived here, you are no doubt aware that this is Earthquake Country. There modifications to the residence that can be done to improve safety, both inside of the home and in the structure itself. Is your home safe in an earthquake now? If not, it’s always a good time to address it, as quakes are a frequent occurrence here.
General tips and resources
Most injuries from quakes happen things falling on someone, so there’s a great focus on indoor precautions, such as securing book cases and tall pieces of furniture to the walls by bolting them securely in place, strapping water heaters, and so on. If you do a web search for how to make your home earthquake safe or ready, you will find many tips along these lines. If you aren’t familiar with these tips, here is one to get you started:
Required disclosures in California
When you buy or lease a home (for 1 year or more), you are supposed to receive the mandated Homeowner’s Guide to Earthquake Safety, print or digital, as well as information on mold, lead paint, etc. Both the state and also many companies provide these regulatory disclosures, and they are worthwhile reading for anyone living in the Golden State especially. If you implement the home improvement suggestions in these pamphlets, it could not just make your home safe in an earthquake, it could save a life.
Additionally, home owners need to provide a statement they’ve completed regarding earthquake hazards and what is known about them to buyers or those who will lease for 1 year or more. You can see that form here: Residential Earthquake Hazard Report. The questions were written by the state of California, so they are not 100% intelligible to consumers, however, submitting a query to any of the major search engines can provide results on what questions are being asked. Please read and learn to understand what the questions are asking, as they all pertain to safety issues, which for most of us would be paramount.
Sometimes I see sellers answer “don’t know” to every question on the form. That is not helpful. Most sellers do know if their water heater is strapped, and if they have done a pre-sale inspection, the inspector will have told them if the strapping is correct or not. If they don’t know what a cripple wall is, a quick search will tell them whether that question applies at all – and often, it doesn’t. Most houses here do not have brick (aka “masonry”) foundations.
Soft story construction
Question 7 reads of the form listed above says:
If the house has a living area over the garage, was the wall around the garage door
opening either built to resist earthquakes or has it been strengthened?
A a garage or carport with a living area above it is called a soft story (sometimes spelled soft storey) and is more vulnerable to damage from earthquakes because of the large opening at the garage door. This could be a house, a townhouse, a duet home, a condominium, etc. – anywhere there’s a living space over a parking space with a wide opening for cars to pass through. In some cases, there’s only a little overlap between the parking area and the living area above. In others, there are 2 stories above, and no dividers between the carports, so there are a lot of gradations to it. Newer homes, of course, have been engineered better. (I think you are unlikely to see the open carport style in newer construction.)
We see that configuration all the time, yet many people do not understand the vulnerability or that they might want to address it. You can see some scary pics by doing a Google image search for Soft Story Earthquake.
It is possible to improve safety by strengthening or reinforcing the areas on each side of the door frame (if there IS a door frame, sometimes it’s an open carport), and perhaps additional areas, too. The same issue would be at play if you were in a home over a shop with large display windows and not much solid wall directly below you. A structural engineer can give the best advice on home improvements that will make the structure safer in case of a quake.
In some parts of California, there’s a movement to get apartment and soft story building owners to retrofit buildings. Palo Alto has been discussing it in recent years. Los Angeles has been requiring the retrofitting for seismic safety of many buildings mandatory for a couple of years now.
That could be a significant cost but would no doubt save lives in the event of a major seismic strike.
If you are going to purchase a home with a living area over the garage, or have already done so, see if you should bolster the engineering for safety. Some improvements may not be costly, so don’t dismiss it as unfeasible without investigating. If you own a condo with a soft story ground floor, learn what can be done to strengthen the building so there is a lessened risk of collapse.
There are many more issues to making your property more safe in an earthquake that we didn’t touch on here today. Be sure to ask your home inspector or structural engineer how you can make your dwelling more earthquake resistant and more safe in case of shaking and related issues. Read the state guide, linked above, which has great information that every California resident should know.
Here are some related links: