Seismic Retrofit Services

Penhall Retrofit Plans for Seismic Retrofit, Soft Story Seismic Retrofit

Penhall is your top choice for seismic engineering and construction services for every type of seismic retrofitting. Penhall Company is celebrating 60 years of excellent service! Whatever your design build need we are ready assist you with your next seismic retrofitting project.

Penhall has a long history of seismic work. While we possess the resources and capabilities to take on any size contract, we consider no job too specialized, too large or too small. We believe that every project deserves our utmost attention to detail and commitment to client satisfaction. Our clients know they can depend on us to get the job done on time and on target, from start to finish and every step in between. Whatever your needs, wherever you’re located, trust Penhall Seismic retrofit services do it right.

Seismic Retrofitting Service at Penhalll

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Buildings at Risk from Seismic Events

Soft Story

Currently in California the most common type of seismic retrofitting is called soft-story retrofit.  The weak wood frames are often seen in multifamily apartment dwellings with tuck under parking.  This style of  building is a common design in both San Francisco and Los Angeles. Due to multiple seismic retrofit ordinances in the State of California cities like San Francisco and Los Angeles have already begun engineering and construction to become compliant. Other cities are following suit like Santa Monica and West Hollywood.  We expect many more cities to jump in line to become compliant with new seismic safety standards.   Common solutions for soft-story retrofitting are steel special moment frames, cantilevered column solutions, or shear wall paneling.

Non-Ductile Concrete

Another type of seismic retrofitting includes non-ductile concrete buildings. Often seen in multi-story buildings built pre 1978 before seismic codes were tightened. The buildings are considered reinforced concrete in design, but  often don’t have enough steel reinforcement to handle a major seismic event. While there are several combinations of solutions for non-ductile concrete steel beam installations and polymer fiber wrap solutions are often used to retrofit non-ductile concrete buildings.

Unreinforced Masonry (URM)

URM construction is another type of seismic retrofit that Santa Monica is most recently preparing for. This type of construction often seen on older historic buildings has no metal or steel reinforcements at all and is literally often only brick and mortar. A common solution is to center core or drill through the bricks vertically and thread rebar or steel through and pour back concrete to secure hole.

Penhall launched operations nearly 60 years ago supporting southern California with a singular commitment to providing the highest level of services to its clients. Since then, Penhall has expanded its reach, scope and expertise, serving clients across the U.S. and beyond. Today, Penhall encompasses 41 strategic locations and employs more than 1,200 professionals, with current and ongoing expansion into Canada. We’ve dedicated that last 60 years to honing our specialized seismic, scanning and concrete services.

FRP Installation

Penhall Company Seismic Retrofit Services department is proud to be a certified applicator of advanced composite materials, often referred to as fiber reinforced polymer (FRP).

This material is used to strengthen structures in the same way that steel would, but an added benefit is that these composite materials add significantly less weight. FRP systems can be used to strengthen reinforced concrete and unreinforced masonry walls, if deemed the best solution for your building’s retrofit needs. This strengthening solution has been utilized in thousands of retrofit and strengthening projects and has proved to perform very well in the event of earthquakes.

For more information on FRP systems, call us today to speak to one of our certified applicators.

Common Soft Story Retrofit Solutions

What are moment frames?

  • A moment frame is a system of columns and beams that are connected to one another with fully and/or partially restrained connections.
  • A special moment frame is expected to withstand significant inelastic deformation as a result of lateral forces. They are used typically in mid/high-seismic regions and are significantly more expensive than other retrofit options.

What are cantilever columns?

  • A cantilever is a horizontal beam that is unsupported at its end.
  • A cantilever column is the vertical component that supports the horizontal cantilever beams.

What are shear walls?

  • A shear wall is a vertical-oriented wide beam that transfers lateral forces from exterior walls, floors, and roofs to the ground foundation.
    vertical-oriented wide beam also known as a sheer wall

What is destructive testing?

  • Destructive testing is the process of determining design weaknesses.
  • For seismic retrofit projects, the city would like to see the quality and connections of load-bearing beams that are at-risk of failure in the event of an earthquake prior to approving permitting for the project.
  • This type of testing requires exposure of these connections.

ZOOMED IN Destructive testing area to determine design weaknesses. ZOOMED OUT Destructive testing area

What is non-destructive testing?

  • Non-destructive testing is the process of evaluating materials or components for discontinuities or differences in characteristics without causing damage to the structure.
  • Ground penetrating radar uses radio waves to scan concrete.
  • Concrete x-ray uses x-rays or gamma rays to image the interior of a concrete target to identify embedded objects.

Ground penetrating radar being used to locate imbedded hazards GPR Analyst Scanning a concrete slab to locate post tension cable

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Latest News

Pfeiffer Canyon Bridge Reopening

Bridges all over California (and elsewhere) are undergoing improvement projects to ensure their security in the case of a large earthquake- some preemptively and some by necessity. Most recently the Pfeiffer Canyon Bridge, which runs on Monterey County’s Highway 1, has reopened after major damage- which nearby residents are thrilled about.

The newly constructed bridge, which is now made of steel, was built in replacement of the original concrete bridge that was severely damaged following a severe winter storm in February. 30 miles of this very essential bridge was closed for eight months while repairs were made. 

Many businesses in Big Sur suffered from the loss of traffic coming through the tourist destinations, with many tourists and residents unwilling to make the hike. Some businesses even closed their doors while the bridge was under construction.

The bridge, which opened last month, was a joyous occasion for residents and business owners who celebrated with a grand opening the day that it was officially ready to be driven on again.

The fact that this bridge was able to be completed so quickly is quite amazing. One estimate stated that a project as large as this one could have taken as long as 10 years to complete. However, with a dedicated team of professionals who worked tirelessly through holidays and weekends, the bridge repair was able to be completed in a mere eight months.

Penhall Company was involved in the final portion of the bridge repair. Using a Penhall G-38 grinder, Penhall Company’s team ground the bridge and gave the proper texture to the bridge- as required by CalTrans. Penhall Company finished their work two days before the bridge’s grand opening.

Thankful for all those involved in the Pfeiffer Canyon Bridge reconstruction process for making it a success and safer for all of those who use it.




November 22, 2017

Average Time Of A Retrofit

 The answer to this question depends on a variety of factors, mainly the size and scope of your individual seismic retrofit project. Each property is unique and requires a different solution than another, so understand that your project may be shorter than the average project or longer than average project.

The process is as follows:

1. Once you have chosen your engineer and contractor for your seismic retrofit the process can be broken into three steps. The engineering process tends to take, on average,  2-4 weeks. Your property needs to be assessed and it takes time for the engineer to determine the best seismic solution for your property. 

2. Once your engineer has returned with the plans they must be submitted to the city for approval. The city will determine if the plans the engineer has proposed are appropriate. This can take as little as 6 weeks and up to 12 weeks. If desired, an expedited plan check is available though there is a fee associated with this service.

3. Once the plan is checked and approved, construction can begin. The time for construction is dependent on the size of the property that is being retrofitted. On average construction takes 30 days but this time frame will increase if the complex is larger.

When the engineering process is completed, the construction portion of the retrofit begins.

As mentioned, time can vary considerably based on the size and scope of the work. On average, construction takes approximately 30 days. However larger and more complex work requires more time (greater than 30 days).

The retrofit process may seem daunting, especially considering that some may even have been unfamiliar with the term “seismic retrofit” prior to receiving their notice. However, there are great resources to learn everything you need to know about the seismic retrofit process.

Visit our blog weekly for more information on retrofitting in California.



References include:

November 17, 2017

Seismic Retrofit Solutions: Fibrwrap ®

The new seismic retrofit ordinances passed in cities across California have prompted many property owners to consider the best possible solution for their property’s retrofit, with the help of a professional engineer. While there are a variety of solutions for a seismic retrofit based on building type, the use of fiber reinforced polymer systems can be a creative and cost-effective solution for a building’s retrofit.

Penhall Seismic Retrofit Services spoke with Scott Arnold, the Director of Engineering Solutions for Fyfe Co LLC., about the state of seismic retrofitting today- especially following the recent, devastating earthquakes in Mexico and elsewhere. Fyfe Co. is a producer of Tyfo® Fibrwrap ® Composite Systems that have been utilized on a variety of retrofit projects around the world.


Question: Do you feel that recent earthquakes (here and abroad) have prompted property owners as well as cities to be more diligent in seismically strengthening their buildings?

Scott Arnold: Yes. More awareness to these events and observed damage and loss of assets has prompted legislation to address potential issues. It is a slow moving process, but clever owners will retrofit sooner than later in order to protect their assets and also save money. These retrofits don’t get less expensive as time goes by.


He is certainly correct in saying that retrofits do not lower in cost as time goes by. As the deadlines for retrofitting in California cities loom, it may be even more difficult to complete the retrofit as demand grows. In addition, when people began to see the footage of buildings collapsing in Mexico it made clear to many the danger of having seismically unsafe buildings- especially in an earthquake prone state like California. Buildings and structures that have been seismically strengthened can save lives in the case of a large earthquake.


Question: Do you have any comments on the state of seismic retrofitting today compared to how it was 30 years ago?

Scott Arnold: There is just as much, if not more, required seismic retrofits today as there were 30 years ago. The codes are updated every three years and mother nature is due to give us another remind any day now. Our technology is more accepted today than it was in the past, so I believe we are well positioned to capture quite a bit of necessary work.


There have been multiple earthquakes in California over the last 30 years that have reminded us all of the importance of seismic safety in building, particularly the Loma Prieta earthquake in 1980 and the Northridge earthquake in 1994. Thankfully, technological advances in seismic retrofitting have allowed for less invasive solutions that are also cost-effective.


Question: Tyfo® Fibrwrap ® has been utilized on thousands of retrofit projects around the world. How does it feel to know that this material is not only saving lives, but also keeping buildings habitable following a large earthquake?

Scott Arnold: Solving structural problems in a more clever and cost-effective manner is quite satisfying, but I really realize the true value when I consider the fact that we have really helped protect our citizens and make our infrastructure much more resilient.


Beyond anything else, seismic strengthening in California and elsewhere is intended to save lives. Regardless of your building type- whether it is soft story, non-ductile, or URM, consider the seismic retrofit options in your area to ensure the safety of yourself, your loved ones, and your investments in the case of a large earthquake.

Penhall Seismic Retrofit Services is very excited to be a certified applicator of Tyfo® Fibrwrap ®.


November 10, 2017