Questions and Answers
What could happen to an unbolted home in the next strong earthquake?
The house could slide off its foundation and possibly collapse. more »
What is the cost of a seismic retrofit for a typical home?
As low as $3,600, many between $3,600 and $6,000. more »
Will bolting really increase the value of my home on the open market?
Given a choice between two properties, a potential buyer will naturally choose the more secure home, or expect to pay less for the seismically deficient home.
My home was built after 1980 do I need a seismic inspection
Many homes built after 1980 will not withstand an earthquake which a properly secured home will. Inspections of post 1980 constructed homes which failed in earthquakes in the San Francisco Bay area showed that the bolting method was incorrect and the major reason why the homes fell off their foundations.
My house has survived for 70 years. Why should I get house bolting now?
Since your home was built there has not been a strong quake in our area. You should retrofit your home because it is a preventative measure to minimize the damage to your home and maximize the safety of your family in the event of an earthquake. more »
I have heard that bolting can actually cause greater damage. What can I believe?
This is a misconception. Not bolting your house is like saying, "I don't have brakes on my car because, if you put them on too hard, you could bump your head". more »
What are cripple walls/pony walls? Why are they so dangerous?
A cripple wall is a short stud wall that extends from the top of the perimeter foundation upward to carry the floor joists. The danger comes from the fact these components are in the seismic load path and are often inadequately braced. They can collapse like dominos in a large earthquake.
I have a brick chimney on my house does this needed to be protected for earthquakes?
All brickwork and masonry is rigid and in an earthquake is highly prone to cracking and falling. Chimneys and other masonry should be inspected to ensure that it is in proper condition and properly secured to prevent failure in an earthquake.
Can any type of foundation be reinforced?
Any foundation can be made safer. There are different solutions for different materials. A brick foundation can be retrofitted with embedded anchor bolts, and deteriorated mortar can then be flushed out and reconditioned with high density mortar.
My stone foundation seems to be falling apart. Is it too late for me to think about reinforcement or foundation repair?
Not at all! In fact, foundation repair can restore your foundation to better than its original integrity. Then we can anchor the house to it using state-of-the-art materials and specialized seismically engineered procedure.
What else should I do to preserve my home?
In a very basic sense maintenance is preservation. Caring for all aspects of your building will help maintain its structural strength. Repointing (fixing) mortar joints, replacing rotted wood members, and making sure water runs away from the foundation will help preserve a building, even in an earthquake.
Are earthquakes truly inevitable?
Yes. more »
What causes an earthquake?
An earthquake is a natural shaking of the ground, caused by the sudden slipping of rock on a fault-line. A fault line is the point where tectonic plates meet. Seismic waves spread outward from the fault rupture much like ripples do in a quiet pond when a stone is thrown into it. Sometimes the plates only jump a tiny bit causing windows to rattle. Other times the displacement is so violent that it sends seismic waves booming out in all directions with forces similar many atomic bombs. The result is called an earthquake.