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 Seismic retrofitting is the modification of existing structures to make them more resistant to seismic activity, ground motion, or soil failure due to earthquakes. With better understanding of seismic demand on structures and with our recent experiences with large earthquakes near urban centers, the need of seismic retrofitting is well acknowledged. Prior to the introduction of modern seismic codes in the late 1960s for developed countries (US, Japan etc) and late 1970s for many other parts of the world (Turkey, China etc), ^[1], many structures were designed without adequate detailing and reinforcement for seismic protection. In view of the imminent problem, various research work has been carried out. Furthermore, state-of-the-art technical guidelines for seismic assessment, retrofit and rehabilitation have been published around the world - such as the ASCE-SEI 41 ^[2] and the New Zealand Society for Earthquake Engineering (NZSEE)'s guidelines ^[3].

The retrofit techniques outlined here are also applicable for other natural hazards such as tropical cyclones, tornadoes, and severe winds from thunderstorms. Whilst current practice of seismic retrofitting is predominantly concerned with structural improvements to reduce the seismic hazard of using the structures, it is similarly essential to reduce the hazards and losses from non-structural elements. It is also important to keep in mind that there is no such thing as an earthquake-proof structure, although seismic performance can be greatly enhanced through proper initial design or subsequent modifications.

Foundation Inspection

Our initial service starts with the performance of a detailed specialty inspection in order to determine the condition of the foundation on a single family home or a multi-family building. This involves a thorough inspection of not only the foundation area itself, but also the exterior perimeter and interior of the building as well.

The interior of the building gives many clues of what has, is or may be occurring underneath. The exterior inspection is most commonly concerned with any potential moisture issues that could adversely affect the foundation system. Having viewed the building interior and exterior, our inspector then has a true relative perspective so that when he is under the house, key areas of concern can be isolated in relation to his interior and exterior findings.

By viewing a building from all three of these perspectives (interior, exterior, and underneath), we are able to achieve a level of certainty that allows us to then write a corrective prescription that is most appropriate to that particular building.

That information is provided to the client in the form of what we call a "Summary of Findings." This is a narrative explanation that details our observations, our advised correction and a precise cost for us to do the work should we be requested to do that at a later date. We deliver this summary to the client via e-mail, usually the next business day following the actual inspection.

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Inspections for Insurance Compliance

We also perform inspections to comply with insurance forms requesting "bolting status." We will come to your home and inspect the foundation regarding the status of the bolting when requested by you on behalf of your insurance company. We are authorized to fill out the insurance company provided forms and if any work is needed to bring your home into compliance, we can perform that work as well.

Additionally, we will also provide a "Summary of Findings" as detailed in the last paragraph of the section above entitled "Foundation Inspections."

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House Bolting (Seismic Retrofitting)

Seismic retrofitting is the process of adding additional hardware, plywood, and framing lumber to the foundation area of a building in a way that heightens its readiness and helps protect it during seismic activity. There are very specific methods of how this is to be done and unfortunately many wrong ways to do it as well! If your house is built later than 1936, it almost certainly has some level of "bolting" in place from when it was first built. Standards have of course evolved tremendously since then (imagine the safety difference in a 1936 car compared to a current one!) and this is where seismic retrofitting (bolting) comes in. It is employing current structural knowledge into an otherwise antiquated situation to improve its overall ability to withstand earthquake movement and to help protect you from catastrophic loss.

We perform full seismic retrofitting ("house bolting") to current standards. The exact specifications of this work can be viewed directly via the City of Los Angeles website at www.ladbs.org. Even if you do not live in Los Angeles itself, all cities that we work in recognize the Los Angeles standards and accept them on all work we perform. This includes, but is not limited to, Glendale, Burbank, West Hollywood, Beverly Hills, Pasadena, South Pasadena and Culver City. Other cities also apply, though these are the areas we service most often.
We also perform corrections of incorrectly performed or antiquated bolting jobs in order to help protect thosehomes from future earthquakes. (Statistic: 85% of homes within various cities of Los Angeles county that have been "bolted" since the 1994 Northridge earthquake had the work performed sub-standardly when it was done.)

Therefore, only about 15% of the inspections we perform find houses to be properly and fully retrofitted. This includes houses that have been "retrofitted" after the 1994 Northridge earthquake. If your foundation retrofit is sub-standard in some way, we will be able to provide you a recipe of correction to resolve that deficiency and help protect your home from loss in any future earthquakes  .Back to top