Seismic Retrofitting Services

Are you thinking about getting earthquake insurance?
If you are a homeowner in earthquake territory, we recommend getting your home seismic retrofitted. Insuring your home will help cover the costs of the damage that an earthquake can cause to your home, but seismic retrofitting can cut down or prevent that damage from occurring entirely.

Seismic retrofitting will give your home a better chance to stand up to devastating earthquakes. It strengthens the foundation of your home so that it can stand tall through the violent tremors that quake in our area cause.

With seismic retrofitting, your home will be a safer place to be when the next earthquake comes. Keep your family safe and your home standing upright with our seismic retrofitting services.

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    Why Homeowners Should Retrofit

    We know the safety of your family is the most important thing to you. This is a factor that goes through the head of every homeowner when they are considering whether or not to retrofit their home. As important as this is, keeping your family safe is not the only benefit that retrofitting your home will give to you, however.

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    Give Your Property a Chance to Withstand an Earthquake

    If you decide not to retrofit your home, you are gambling with the most expensive asset that you own. It’s only a matter of time until the next major earthquake occurs, and when it does, the odds of your home with standing it is drastically decreased if you do not have a home that is retrofitted. You can greatly reduce the chances that you lose your home entirely by retrofitting it for earthquakes.

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    Retrofitting Can Cut Down on Insurance Premiums

    Insurance premiums are based on two simple factors:

    • How likely the event is to occur
    • What is the expected cost to repair damages after the event occurs

    The higher either of these factors is, the more your insurance premiums will be.

    As far as earthquake insurance premiums go, the only way to change the former is to move your location, since the chance of an earthquake is geologically based.

    The factor that we do have control over is the expected amount of damage that that your house takes on after the earthquake occurs.

    By retrofitting your house, it will be able to better withstand the anticipated damage that it will take on in the event of an earthquake. This, in turn, will decrease your insurance premiums.

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    It’s Better to Pay Now Then after the Damage Has Been Done

    Seismic retrofitting can make a huge difference on the damage your house takes after an earthquake. To explain this in dollars, retrofitting can mean the difference between minor repairs for a few thousand dollars, vs major repairs that can cost hundreds of thousands of dollars.

    Real-World Example

    Michael O’Hearn is an architect and living proof for why retrofitting your home is a good investment. He owned two houses on the same block.
    Both houses were identical:

    • They were both roughly the same age (approx. 100 years old)
    • They use the same building design with the same materials
    • Theywere built with the same construction techniques

    Basically, they were identical houses that were right next to each other.
    In 1989, the Loma Prieta Earthquake occurred. One house suffered minor damage and the other broke into four different pieces.
    What Was the Difference?
    Seismic Retrofitting
    One house, the house that only took on minor damage, was retrofitted to withstand such an earthquake. The other house was not.
    The house that held up to the earthquake had sheer walls bracing the cripple wall framing and the wall framing was sill plate bolted to the foundation.
    O’Hearn had plans to do the same for the other house, however, he did not do it in time before the earthquake hit.
    The Aftermath
    O’Hearn had two repair bills after the quake hit. The bill for the retrofit house was $5,000, and the bill for the other house was $260,000.


Request a seismic retrofit inspection TODAY!
FREE Seismic Retrofit Inspection Offer
Simply fill out our request form to get a free inspection from us. That’s a $600 value on the house! We provide foundation inspections, drainage inspections, soft story inspections and structural inspection services for your home.

The Process of Seismic Retrofitting

The process of seismic retrofitting most often involves three steps – bolting the foundation, bracing the cripple wall, and attaching the cripple wall to the floor framing.

Foundation Bolting

Foundation bolting involves tying the wood framing members along the walls of the building to the concrete foundation. If this is not done, the house could slide away from the foundation entirely if anearthquake is strong enough.

Foundation bolting is done by inserting 5/8” anchor bolts 7” through the mudsill and into the concrete foundation. It strengthens the connection between the wood framing of your home and the concrete. We often find that existing bolts are spaced too far apart, or rusted to the point where they will not provide enough support for the foundation.

Bracing the Cripple Wall

Older homes have a cripple wall;a wood-framed wall found in the crawlspace that extends from the concrete foundation stem wall to the floor joists. In the event of an earthquake, the cripple wall will take on most of the impact.

The cripple wall is typically the weakest part of your home. If you live in an older house, reinforcing the cripple wall will allow to better withstand an earthquake.

Cripple walls are braced using structural grade plywood. This helps fortify the cripple wall and make it less likely to collapse when an earthquake occurs.

To brace the cripple wall, 1/2” 5-ply APA rated plywood sheathing is covered with galvanized wire mesh screens. Ventilation holes are cut and it is nailed to the existing cripple wall framing. In order to brace a cripple wall that is larger than 4 feet, a city-appointed structural engineer must be involved.

Securing the Cripple Wall to the Floor Framing

Framing anchors are used to attach the cripple wall to the floor. This further strengthens the cripple wall and its ability to stand up to earthquakes. Simpson A-35 Framing Anchors are used to connect the cripple wall to the floor framing.