Your Earthquake Retrofit Experts In Sonoma County

Sonoma County Earthquake Retrofit

Earthquake Protection Is An Important Consideration In The North Bay Area

Since we in the North Bay, Sonoma County, experience ongoing upheaval in the earth beneath us, Earthquake Protection is an important consideration. Not all Contractors are qualified for this work as it requires extensive training and knowledge of both building code requirements and experience in this area of service. Since a recent study by the Pacific Earthquake Engineering Research (PEER) Center estimates that the owners of retrofitted houses can save between $10,000 and $200,000 in repair costs resulting from a major earthquake, contacting Bielefield Construction Inc. to have them brace and/or bolt your home with a seismic retrofit in Sonoma County.




Sonoma County Earthquake Home Preparedness


Earthquake Retrofit Requirements for General Contractors

An earthquake retrofit is a seismic retrofit, it’s also known as a “brace+bolt retrofit“, “house retrofit”, “foundation bolting”, or simply a “bolt down”. It is the process of improving the connection between the wood frame and the concrete foundation of a house.

The earthquake brace and bolt program is a grant program designed for eligible California homeowners to provide up to $3,000 toward a residential seismic retrofit.

During an earthquake, the ground moves and shifts from under the house, but gravity and inertia try to hold the structure in place, and that’s when things begin to break. Homes and structures with weak foundation-to-frame connections tend to experience massive damage along entire sections of a home.

Millions of homes in California are wood-framed houses that need a brace and bolt retrofit to prevent them from sliding off their foundation. There are other types of concrete homes also vulnerable to shake damage, for different reasons.

Before we dig deeper into the earthquake retrofit requirements, we must review house types to learn about their vulnerabilities.

  • Raised Foundation Houses – These houses are built underneath the first floor, which is referred to as a crawl space. These types of houses can shift off their foundations from shaking. They are strengthened by bolting the house to its foundation with anchor bolts, or with bracing and bolting.
  • Stem-Wall Houses- These homes have raised foundations or slide off the structure to preserve them from earthquakes. Normally, they have a wood-framed first floor, which rests directly on a raised perimeter concrete foundation.
  • Cripple-Wall Houses- Cripple-wall (“crawl space”) houses also have raised foundations with a crawl space under the house, with short (less than full-story height) wood-framed walls between the foundation and the wood-framed first floor.
  • Post & Pier Houses- These houses have a raised foundation, but the wood frame floor is supported only by upright wood posts. The posts rest on individual concrete blocks or pier pads around the perimeter and interior of the crawl space.
  • ADUs build over the garages- Houses built on the garages attached or detached are vulnerable to damage from earthquakes because the walls and door(s) are not often reinforced for shaking. These are often called “soft story” residences. Retrofitting the garage space can make it more resistant to earthquakes.
  • Hillside Houses- Houses built on hillsides or steep slopes are often set on tall, narrow posts or columns, with walls stepping down the hill. The foundation is often expected to bear the weight of the entire house but the structural elements found in these types of houses are not designed to be able to withstand shaking. Retrofitting these houses becomes a must.

Depending on the house type, the retrofitting requirements vary. A major requirement involves strengthening the foundation by applying various solutions like brace and bolts, wood frames, and so on.

An earthquake’s shaking motion can cause severe damage to older homes. So, the most important requirement is to know the building type and exactly provide the needed solution.

It is the responsibility of every house owner to check –  Contact Us today and take advantage of our consultation services. We will work closely with you so you can know the peace of mind that comes with knowledgeable Retrofitting Services.