CFS Designer™ v2.5 Makes Cold-Formed Steel Design Easier Than Ever

With the use of engineering software tools, structural engineers can design buildings faster and more efficiently than ever before. In this blog post, Clifton Melcher, P.E., a senior project manager for cold-formed steel connectors, discusses the various enhancements included in version 2.5 of Simpson Strong-Tie® CFS Designer™ software.
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What Building Professionals Need to Know About Construction Loading

Understanding construction loading is important as it relates to the acceptable practices in terms of staging and storing construction materials prior to installation. What does “construction loading” mean? This term describes materials and people that are present during the course of construction. It refers to any construction material that is stacked and/or staged on the trusses for any length of time prior to the installation of said materials. This also includes those individuals that are working or walking on the trusses during the course of construction.

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Turkeys and Gratitude

This week’s post was written by Kari Martin, Marketing Communications Content Manager at Simpson Strong-Tie. 

There are a couple of turkeys that like to hang out around our home office in Pleasanton and, no, I’m not referring to any of my colleagues — we actually have a gang of wild turkeys that comes up from the creek behind the office. Almost every day, these colorful birds feel safe enough to stroll onto the office walkway pecking for food outside our office windows and doors. It’s surprising to me that these beautiful creatures could be so fearless (or is it simply naïve?), especially around Thanksgiving time. Their presence reminds me that being fearless is important, because nothing new would ever be discovered if we were too afraid to venture outside our comfort zones.

The beauty and strangeness of the turkeys also remind me to be thankful, because everything we have in life is ultimately a gift. Their consistent return to our office is a gentle reminder as I walk into work to give thanks to you, our readers, our customers and our partners every day. Thank you!

We hope you enjoy the holiday with your family and friends. We’ll be back with another post next week.

Drop, Cover, and Hold On – Becoming Earthquake-Smart in the 2017 Great ShakeOut

This week’s post was written by Jacob McAuley, Associate Regional Marketing Manager at Simpson Strong-Tie.

Every October, millions of people across the globe participate in earthquake drills as part of an event called the Great ShakeOut in order to improve their earthquake preparedness. This year, the Great ShakeOut took place on October 19 and involved more than 60 countries. In addition to the earthquake drill, participants in the event often take part in other activities such as seminars, Q&As and more. At Simpson Strong-Tie, we practiced earthquake drills at each of our major branches, and, in our Pacific Northwest region, we were part of a Reddit Ask Me Anything event (an online live Q&A) to talk about earthquake safety and answer people’s questions. Below, I discuss our participation in both of these activities.
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The Cold-Formed Steel Construction Catalog is HOT off the press!

The SE Blog is taking some time off for the 4th of July holiday this week. However, we’ve just released the 2017 edition of our Connectors for Cold-Formed Steel Construction catalog – order a hard copy to be mailed to your office or download a PDF copy and start using it today!

Connectors For Cold-Formed Steel Construction

The C-CF-2017 is a 308-page catalog including specifications, load tables and installation illustrations for our cold-formed steel connectors and clips, helping you easily specify and install in commercial curtain-wall, mid-rise and residential construction.


4 Common FRP Myths and Misconceptions: The Stuff Not Everyone Talks About

The primary benefit of fiber-reinforced polymer (FRP) systems as compared with traditional retrofit methods is that significant flexural, axial or shear strength gains can be realized using an easy-to-apply composite that does not add significant weight or section to the structure. Many times it is the most economical choice given the reduced preparation and labor costs and may be installed without taking the structure out of service. However, it is important to make sure the composite is properly designed following industry standards in order to ensure that it is the right product for the application.

To provide you with a better understanding of the topic, it’s important to dispel some common myths and misconceptions that you might hear about FRP:

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SEAOSC Safer Cities Survey Results: How Are We Building Strength and Transparency in Our Communities?

Back in January, employees at Simpson were given the opportunity to learn more about the 401K retirement and investment plan. The big takeaways from my training session were a) save as much as you can as early as you can in life and b) use asset allocation to diversify your portfolio and avoid too much risk. Now, I’m not a big risk taker in general, so I dutifully picked a good blend of stocks and bonds with a range of low to high risk. It seems like a pretty sound strategy and it made me think of all the other ways I tend to minimize risk in my life. When I head to a restaurant, for example, I almost instinctively look for the county health grade sign in the window. When my husband and I went to go buy a new family car a couple years ago, I remember searching the National Highway Traffic Safety Administration (NHTSA) website for crash test ratings. Even when I’m doing something as mundane as having a snack, I will invariably flip over the Twinkie package to see just how many grams of fat are lurking inside (almost 5 per serving!). For all the rankings and information available to the general public for restaurants, cars and snacks, there isn’t much, if any, information to help us know if we’re minimizing our risk for one of the most common activities we do almost every day: walking into a building.

Risk level knob positioned on medium position, white background and orange light. 3D illustration concept for business security management.

 

Now before you accuse me of being overly dramatic about such a trivial activity, here’s some food for thought: research has shown that Americans spend approximately 90% of their day inside a building. That’s over 21 hours a day! Have you ever once thought to yourself, “I wonder if this building is safe? Would this building be able to withstand an earthquake or high wind event?” Or how about even taking a step back and asking, “Are there any buildings that are already known to be potentially vulnerable or unsafe, and has my city done anything to identify them?” Unfortunately, that kind of information about a city’s building stock is not usually readily available, but some in the community, including structural engineers, are working to change that.

Los Angeles skyline on a partly cloudy day with a row of palm trees in the foreground.

 

The charge is being led in California, a.k.a. Earthquake Country, where structural engineers are teaming up with cities to help identify buildings with known seismic vulnerabilities and provide input on seismic retrofit ordinances. Structural engineers have learned quite a bit about how buildings behave through observing building performance after major earthquakes, and building codes have been revised to address issues accordingly. However, according to the US Green Building Council, “…the annual replacement rate of buildings (the percent of the total building stock newly constructed or majorly renovated each year) has historically been about 2%, and during the economic recession and subsequent years, it’s been much lower.” This means that there are a lot of older buildings out there that have not been built to current building codes and were not designed with modern engineering knowledge.

Several cities in California have enacted mandatory seismic retrofit ordinances that require the strengthening of some types of known vulnerable buildings, but no state or nation-wide program currently exists. The Structural Engineers Association of Southern California (SEAOSC) recently decided to launch a study of which jurisdictions in the southern California region have started to take the steps necessary to enact critical building ordinances. According to SEAOSC President Jeff Ellis, S.E., “In order to develop an effective strategy to improve the safety and resilience of our communities, it is critical to benchmark building performance policies currently in place. For southern California, this benchmarking includes recognizing which building types are most vulnerable to collapse in earthquakes, and understanding whether or not there are programs in place to decrease risk and improve recovery time.” These results were presented in SEAOSC’s Safer Cities Survey, in partnership with the Dr. Lucy Jones Center for Science and Society and sponsored by Simpson Strong-Tie.

safer-cities-ca

This groundbreaking report is the first comprehensive look at what critical policies have been implemented in the region of the United States with the highest risk of earthquake damage. According to the Los Angeles Times, the survey “found that most local governments in the region have done nothing to mandate retrofits of important building types known to be at risk, such as concrete and wooden apartment buildings.”

The Safer Cities Survey highlights how the high population density of the SoCal region coupled with the numerous earthquake faults and aging buildings is an issue that needs to be addressed by all jurisdictions as soon as possible. An excerpt from the survey covers in detail why this issue is so important:

No building code is retroactive; a building is as strong as the building code that was in place when the building was built. When an earthquake in one location exposes a weakness in a type of building, the code is changed to prevent further construction of buildings with that weakness, but it does not make those buildings in other locations disappear. For example, in Los Angeles, the strongest earthquake shaking has only been experienced in the northern parts of the San Fernando Valley in 1971 and 1994 (Jones, 2015). In San Bernardino, a city near the intersection of the two most active faults in southern California where some of the strongest shaking is expected, the last time strong shaking was experienced was in 1899. Most buildings in southern California have only experienced relatively low levels of shaking and many hidden (and not so hidden) vulnerabilities await discovery in the next earthquake.

 The prevalence of the older, seismically vulnerable buildings varies across southern California. Some new communities, incorporated in the last twenty years, may have no vulnerable buildings at all. Much of Los Angeles County and the central areas of the other counties may have very old buildings in their original downtown that could be very dangerous in an earthquake, surrounded by other seismically vulnerable buildings constructed in the building booms of the 1950s and 1960s. Building codes do have provisions to require upgrading of the building structure when a building undergoes a significant alteration or when the use of it changes significantly (e.g., a warehouse gets converted to office or living space). Seismic upgrades can require changes to the fundamental structure of the building. Significantly for a city, many buildings never undergo a change that would trigger an upgrade. Consequently, known vulnerable buildings exist in many cities, waiting to kill or injure citizens, pose risks to neighboring buildings, and increase recovery time when a nearby earthquake strikes.

1994-northridge

The survey also serves as a valuable reference in being able to identify and understand what the known vulnerable buildings types are:

  1. Unreinforced masonry buildings: brick or masonry block buildings with no internal steel reinforcement — susceptible to collapse
  2. Wood-frame buildings with raised foundations: single-family homes not properly anchored to the foundation and/or built with a crawl space under the first floor — possible collapse of crawl space cripple walls or sliding off foundation
  3. Tilt-up concrete buildings: concrete walls connected to a wood roof — possible roof-to-wall connection failures leading to roof collapse
  4. Non-ductile reinforced concrete buildings: concrete buildings with insufficient steel reinforcement — susceptible to cracking and damage
  5. Soft first-story buildings: buildings with large openings in the first floor walls, typically for a garage — susceptible to collapse of the first story
  6. Pre-1994 steel moment frame buildings: steel frame buildings built before the 1994 Northridge earthquake with connections — susceptible to cracking leading to potential collapse

1933-earthquake-shot

Along with the comprehensive list of potentially dangerous buildings, the survey also offers key recommendations on how cities can directly address these hazards and reduce potential risks due to earthquakes. As a good starting point, the survey recommends having “…an active or planned program to assess the building inventory to gauge the number and locations of potentially vulnerable buildings…is one of the first steps in developing appropriate and prioritized risk mitigation and resilience strategies.

Economic costs can be substantial for businesses whose buildings have been affected by an earthquake. After a major seismic event, a structure needs to be cleared by the building department as safe before it can be reoccupied, and it will generally receive a green (safe), yellow (moderately damaged) or red (dangerous) tag.  A typical yellow-tagged building could take up to two months to be inspected, repaired and then cleared, meaning an enormous absence of income for businesses. The survey offers a strategy for getting businesses up and running quickly after an earthquake, in order to minimize such losses. The Safer Cities Survey recommends that cities adopt a “Back-to-Business” or “Building Re-Occupancy” program, which would “create partnerships between private parties and the City to allow rapid review of buildings in concert with City safety assessments…Back-to-Business programs…[allow] private parties to activate pre-qualified assessment teams, who became familiar with specific buildings to shorten evaluation time [and] support city inspections.

oes-inspectors-program

Basically, a program like this would allow a property owner to work with a structural engineer before an earthquake occurs. This way, the engineer is familiar with the building’s layout and potential risks, and can plan for addressing any potential damage. Having a program like this in place can dramatically shorten the recovery time for a business, from two months down to perhaps two weeks. Several cities have already adopted these types of programs, including San Francisco and Glendale, and it showed up as a component of Los Angeles’ Resilience by Design report.

Ultimately, the survey found that only a handful of cities have adopted any retrofit ordinance, but many cities indicated they were interested in learning more about how they could get started on the process. As a result, SEAOSC has launched a Safer Cities Advisory Program, which offers expert technical advice for any city looking to enact building retrofit ordinances and programs. This collaboration will hopefully help increase the momentum of strengthening southern California so that it can rebound more quickly from the next “Big One.”

We all want to minimize the risk in our lives, so let’s support our local structural engineering associations and building departments in exploring and enacting seismic building ordinances that benefit the entire community.

For additional information or articles of interest, please visit:

Three Pieces of Advice for Structural Engineering Grads

If you are a civil engineering student finishing your degree, you are probably starting to explore all the options and opportunities available in the workforce. While structural engineering may be a specialized discipline, there are many paths and backgrounds that can lead someone into an exciting career that is innovatively transforming modern development in cities and towns all over the world.

We recently interviewed three of our engineers to learn what got them interested in the field and how they pursued their first job and built their career as a structural engineer with Simpson Strong-Tie.

Network and Make Contacts

Structural Engineer Griff Shapack headshot
Griff Shapack

Griff Shapack is an Associate FRP Design Engineer for Simpson Strong-Tie. He has bachelors and master’s degrees in civil engineering from North Carolina State University.

“I started looking for employment opportunities six months before graduation. I was working in a structures lab during graduate school, and the lab manager shared a job description for an Associate FRP Design Engineer at Simpson Strong-Tie with a few students. I knew I wanted to work under a P.E., and had experience and interest in FRP design, so I applied.”

“One of the things I love best about my job is that I get to go out and give presentations to structural engineers with our sales reps and field engineers. It’s great to be able to interface directly with our customers.”

“My biggest recommendations for engineering students is to reach out to people you already know in the industry. Classmates and professors can have valuable contacts at firms where you want to work.” 

Persistence Pays Off – Don’t Give Up

Structural Engineer Jhalak Vasavada
Jhalak Vasavada

Jhalak Vasavada is currently a Research & Development Engineer for Simpson Strong-Tie. She has a bachelor’s degree in civil engineering from Maharaja Sayajirao (M.S.) University of Baroda, Gujarat, India, and a master’s degree in structural engineering from Illinois Institute of Technology, Chicago, IL. After graduation, she worked for an environmental consulting firm called TriHydro Corporation and as a structural engineer with Sargent & Lundy, LLC, based in Chicago, IL. She worked on the design of power plant structures such as chimney foundations, boiler building and turbine building steel design and design of flue gas ductwork. She is a registered Professional Engineer in the State of Michigan.

“When I was in school for my master’s degree in Chicago, my professor recommended that I apply for a job at a firm called Sargent & Lundy. Unfortunately, at the time I applied, there were no openings at the firm, so I took another job until there was an opening. I interviewed there and got the job. It was a wonderful experience because it was in this role that I had the chance to meet my mentor. Having a female mentor was great in terms of real-life experience and advice. In fact, we still keep in touch.”

“When I moved to California, I wanted to find a job that allowed me to do something different. I applied for a job with Simpson Strong-Tie, and it was the best decision ever because I always get to work on new and exciting projects. My recommendation for students is to be persistent in trying to get a job at the place where you want to work.”

Appreciate and Learn from Every Experience That Comes Your Way

Structural Engineer Neelima Tapata
Neelima Tapata

Neelima Tapata is an R&D engineer for the Fastening Systems product division at Simpson Strong-Tie. She works on the development, testing and code approval of fasteners. She joined Simpson Strong-Tie in 2011, bringing 10 years of design experience in multi- and single-family residential structures in cold-formed steel and wood, curtain-wall framing design, steel structures and concrete design. Neelima earned her bachelor’s degree in civil engineering from J.N.T.U in India and her M.S. in civil engineering with a focus on structural engineering from Lamar University. She is a registered Professional Engineer in the State of California.

“I started searching for a job while I was finishing my master’s program. I started the search about a month before I graduated. My first job was in a consulting firm, and it was a fast-paced environment where you learned a lot on your own. My experience working for different consulting firms gave me a chance to concentrate on designing for a niche market, but my current role helps me see the big picture when it comes to design.”

“One of the things that I love most about my current role is that it allows me to take on multiple projects, so I’m always learning something new. It’s very important to stay curious. I also enjoy interacting with different departments in Simpson Strong-Tie. It gives me an opportunity to take on tasks that structural engineers may not normally get, like writing posts for an interesting publication like our Structural Engineering blog!”

“My advice for young structural engineers is to appreciate every experience that life sends your way. You may not realize it at the time, but it all ends up helping you get where you are now.”

If you are going to receive your degree this year or you know someone who is just starting out or looking to take a different path, Simpson Strong-Tie is hiring! We have several job opportunities in our engineering department. Check out our full list of job openings – then bookmark it! https://www.strongtie.com/about/careers/job-posting/engineerjobs

How to Pick a Connector Series: Selecting a Joist Hanger

A quick glance through the Simpson Strong-Tie® Wood Construction Connectors catalog shows that we manufacture at least 29 different models of face-mount wood-to-wood joist hangers, three separate models of face-mount wood-to-masonry hangers, 42 different models of top-flange wood-to-wood joist hangers, four different models of top-flange wood-to-masonry hangers and 15 models of specialty joist hangers. And that’s not even counting heavy truss girder hangers or multiple- member hangers. So it’s no wonder that sometimes it’s difficult to pick exactly the right hanger for your particular application.

There are many things to consider when picking a joist hanger. The first may be what your load requirements are, including their direction. That will sometimes determine the second consideration. Do you want to use a top-flange or a face-mount joist hanger? Top-flange hangers typically have higher down loads with fewer fasteners, but must be installed when there is access to the top of the supporting member and often before the joist is in place. On the other hand, face-mount hangers can be installed after the joist is in place, and can have higher uplift loads, but will use more fasteners.

Speaking of fasteners, any fastener preference can determine your selection of a hanger. Joist hangers can be installed with common nails, screws (SD for lighter hangers and SDS for heavier hangers), or even bolts, for heavy glulam hangers. See here for information on the various fasteners that can be used with our connectors. The Simpson Strong-Tie Wood Construction Connectors catalog does not list allowable loads for joist hangers installed with SD screws, but you can find them here; just click on the link of the product to find its allowable load. Also, if the joist hanger will be installed with pneumatic fasteners, we have a Technical Bulletin on the possible load reductions that will result.

Another thing to consider at the beginning is what types and sizes of members are being connected together. Is your connection all solid-sawn dimension lumber, engineered wood or structural composite lumber, glulam beams, or trusses? All these types of wood products require different hangers.

Furthermore, joist hangers will have different capacities based on the species of wood to which they are being attached. For example, the truss hangers in the table below have allowable loads listed for Douglas Fir-Larch, Southern Pine and Spruce-Pine-Fir/Hem Fir. Most standard solid-sawn joist hangers, on the other hand, will only have two load ratings, DF/SP and SPF.

Top-flange hangers are sensitive both to the species of wood and to the type of engineered wood to which they are attached. Because of that sensitivity, they have to be tested to each different type of engineered wood that could be used as a header and may have different published allowable loads for each type as shown here.

Is the joist framing into the side or top of a concrete/masonry wall? Then a special joist hanger is required. Is the joist connecting to a nailer on top of a steel beam or concrete/masonry wall? Nailers require top-flange hangers and can result in loss of allowable load if you have to use shorter nails, so you need to check that carefully. There are special tables published for nailer loads for top-flange hangers.

Another consideration is the orientation of the members. In a perfect world, all connections will be between perfectly perpendicular members. But in the real world, joists may be rotated side to side (skewed), or up or down (sloped), or some combination of the two. There are a couple of options in those cases. Hangers such as the SUR/SUL series are available pre-skewed at 45 degrees. Adjustable hangers such as the LSU/LSSU series can be adjusted within limits to certain slopes, skews and slope/skew combinations. Simpson Strong-Tie also has the capability to custom-manufacture quite a few types of hangers to any slope or skew within certain limits, based on the hanger. All of these options, including any load reductions required, are listed in the Hanger Options section of the catalog or website. The table there gives the various options available for each product and clicking on an individual hanger in the website table will send you to a page with the specific reductions for each option.

Another important consideration is the installed cost of the joist hanger. Simpson Strong-Tie publishes what we call an Installed Cost Index, where the total installed cost of a hanger, including fasteners and labor, can be compared for related hangers. For example, there are six joist hangers listed in the Solid Sawn section for a 2×6 joist. They are listed in order of increasing Installed Cost Index. To choose one, simply find the one with the lowest installed cost that meets your load requirements.

SE Blog 4

Obviously, this is a lot to think about when trying to choose a simple joist hanger. In order to make choosing a connector as easy as possible for our customers, Simpson Strong-Tie offers two different software tools to help. The first is our old standby, the downloadable Connector Selector. This is a versatile program that will help the user pick a joist hanger, truss hanger, multi-truss hanger, column base, column cap, holdown, mudsill anchor, hurricane tie, multi-ply lumber fastener, embedded anchor bolt or hinge connector. It can be downloaded from here. You can see from this example that the Connector Selector gives several options for nailing of joist hangers that may not be directly listed in the catalog.

For a quick aid in choosing a connector, Simpson Strong-Tie recently developed our Joist Hanger Selector Web App. This is found directly on the strongtie.com website. While not necessarily as versatile as the Connector Selector, it has a much easier-to-use graphic interface where the user can choose any option they wish. Just simply choose the desired hanger type, the header member, the joist member, the fastener type, any hanger options and input any design load requirements, then hit calculate, and your choices show up immediately.

Here is the output shown for the same inputs as the Connector Selector above. The app will initially show only the most common models that provide a solution, but the user can click SHOW ALL MODELS for a more complete list of solutions. The user can also click on the “+” next to the model name to get additional fastener options.

A final consideration in choosing a joist hanger is the finish desired. Simpson Strong-Tie manufactures joist hangers in several different finishes: Standard G90 zinc coating, ZMax® G185 zinc coating, HDG hot-dipped galvanization after fabrication, Type 316L stainless steel and powder-coat painted. The environment where the joist hanger will be installed and the material it will be in contact with (treated wood or other corrosive materials) will both influence which finish should be chosen. Guidance for selecting finishes is found in our literature and on our website. Also remember that the finish of the fastener used needs to match the finish of the connector.

We hope you find these tools helpful the next time you need to choose a joist hanger. Are there any other tools you need to help you specify Simpson Strong-Tie connectors or anchors? Tell us below.