Most of what makes a house vulnerable in an earthquake is fixable, and a good deal of it is inexpensive. Here is what to look for and what it takes to put it right.
What types of problems are there typically with houses?
There are two types of problems associated with seismic damage to dwellings. The first is structural damage, caused by an earthquake in a way that directly affects the ability of the house to stand up. The second is nonstructural damage, which does not affect the integrity of the structure but may prevent you from using the house afterward.
What are common structural deficiencies?
The most common structural deficiencies in houses are related to the foundation. Since the foundation supports the rest of the house, damage there will almost always affect the integrity of the structure.
Unbolted foundations
Many wood-frame homes, typically older housing, are not adequately anchored or bolted to the foundation. Those that are not can slide off the foundation during an earthquake, severely damaging or destroying the house.
Unbraced cripple walls
A cripple wall is the short wall that connects the foundation to the floor of the house and encloses the crawl space. If these walls are not braced with plywood, they can tip over, sending the house crashing down to the foundation.
What are common nonstructural deficiencies?
Even if a house is structurally sound, damage can come from the things inside it. This kind of damage can keep you out of your home and have a significant financial impact on repairs. Toppling items can also cause severe injury. The most common culprits:
How do I fix these problems?
Many of the problems described above can be remedied through simple and inexpensive means. Nonstructural deficiencies can usually be handled with clips and straps bought at a local hardware store, which you can install yourself in an afternoon.
Structural deficiencies are a bigger job and generally call for a general contractor or an engineer. For more on solutions, see the SEAOSD recommendations for bolting foundations and securing furniture.
Keep going
Once your house is in better shape, put a plan in place for your family with Earthquake Preparedness, or read more about what is actually at risk in a major event.