Author: Paul McEntee

A couple of years back we hosted a “Take your daughter or son to work day,” which was a great opportunity for our children to find out what their parents did. We had different activities for the kids to learn about careers and the importance of education in opening up career opportunities. People often ask me what I do for Simpson Strong-Tie and I sometimes laugh about how my son Ryan responded to a questionnaire he filled out that day: Q. What is your mom/dad's job? A. Goes and gets coffee and sits at his desk Q. What does your mom/dad actually do at work? A. Walks in the test lab and checks things When I am not checking things in the lab or sitting at my desk drinking coffee, I manage Engineering Research and Development for Simpson Strong-Tie, focusing on new product development for connectors and lateral systems. I graduated from the University of California at Berkeley and I am a licensed Civil and Structural Engineer in California. Prior to joining Simpson Strong-Tie, I worked for 10 years as a consulting structural engineer designing commercial, industrial, multi-family, mixed-use and retail projects. I was fortunate in those years to work at a great engineering firm that did a lot of everything. This allowed me to gain experience designing with wood, structural steel, concrete, concrete block and cold-formed steel as well as working on many seismic retrofits of historic unreinforced masonry buildings.

Join Me for a WoodWorks Webinar on Acceptance Criteria and Testing Methods for Connectors

I have the privilege of presenting a free WoodWorks webinar, “Testing and Product Evaluation of Products for Wood-framed Construction” on Thursday, October 25 at 10 am PST. Here is the webinar description:

Products that are not covered by the code are used in many if not all buildings. While the code permits a single engineer to review and submit to a building official and a single building official to review and approve a product not covered by the code, many feel a more robust process is needed to ensure that these products meet the code intent. Also, many code or evaluation reports are used not just for one project, but for multitudes of projects in numerous locations. Test setups can affect the performance and load rating of products.

Several private entities have been created over the years to assist the industry by developing public and transparent processes to develop test requirements, load rating requirements, design and detailing requirements, and ongoing quality compliance as well as product evaluation methodologies. This webinar will discuss various acceptance criteria and testing methods used for products used in wood construction, such as ASTM D7147 and ICC-ES AC155 to further advance the knowledge of these test methods and processes for those in the wood construction industry.

This will be a great opportunity for those of us who work in wood frame construction to discuss code and test requirements for connectors and other products for wood. I hope you’ll consider joining us! To register for the webinar, click here.

– Paul

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Designing Steel Roof Deck Attachment for Combined Tension and Shear

In last week’s post I made a reference to California’s golden sunshine. Californians may have to deal with wildfires, earthquakes, and wearing sunscreen year round, but we generally don’t have high wind to worry about. In a previous blog post, Roof Deck Design Considerations for High Wind Events, I discussed some of the general challenges in designing for wind uplift. This week, I wanted to get a little more specific and discuss the standards applicable to steel roof deck attachments.

Historically, procedures for design of structural connections that utilize fasteners recognize the importance of combined loading effects on structural performance. Whether bolts or screws are the connector choice, the metallic structure of steel alloys includes transverse slip planes of relatively low resistance. This results in yield criteria (function that defines the onset of yielding or fracture) that are often limited by load-deformation performance along transverse planes.

October 11 – Buildings At Risk: Earthquake Loss Reduction Summit

I don’t travel too much for work, so the last three weeks has been a bit different from my normal routine. On August 30, I attended an unreinforced masonry retrofit workshop in Memphis, had a sales meeting the following week in St. Louis, and the annual SEAOC convention last week in Santa Fe, New Mexico.

I have been remiss in not talking about an important summit taking place in California next month. SEAOSC is hosting the 2^nd annual Buildings at Risk Earthquake Loss Reduction Summit on October 11 in downtown Los Angeles, California. The summit is a precursor to the “Great California ShakeOut” event that will be held on October 18.The summit will serve as a forum to not only increase awareness of seismic risk, but spur action. This will be an important conference not only for structural engineers working in seismic areas, but for building officials, architects, building owners, insurance companies, and first responders. The sessions will stress the benefits of mitigation and encourage the different stakeholders to work together on solutions.

Early registration for a discounted rate and a chance to win an iPad ends today, but there is still time to register.

– Paul

“Sunny With A Chance Of Earthquake”

With scientists predicting a 99% chance of a 6.7 magnitude earthquake striking Southern California within the next 30 years, California weather forecasters may want to remind residents that the location which gives lots of golden sunshine year round is also one of high seismic risk.

Recent earthquakes in cities similar to Los Angeles, San Francisco and Memphis have served as a reminder of the damage and disruption a major earthquake can have on a community. Through lessons learned from past earthquakes and research performed by the construction industry, there are many tools available geared toward residential buildings to reduce damage and resist collapse.

What’s Most Important To You As A Structural Engineer?

I am attending the 2012 SEAOC-SEANM Convention in Santa Fe, New Mexico this week. I did not realize that Santa Fe is the oldest state capitol in the U.S., first inhabited by Spanish settlers in 1607, and then settled by Don Pedro de Peralta in 1609-1610. The Palace of the Governors, built in 1610, served as the main government building in Santa Fe for nearly 300 years. The current capitol building, known as the Roundhouse, is the only round state capitol building in the U.S. Our airport shuttle driver used to be a tour guide, so we learned a lot on the drive in.Continue Reading

What's Most Important To You As A Structural Engineer?

St. Francis Cathedral, Santa Fe. By Bill Johnson, 2005. Licensed under Creative Commons, some rights reserved.

The first session I attended today was a discussion of recent earthquakes. James Mwangi Ph.D, PE, Associate Professor of Architectural Engineering at Cal Poly, discussed his project to develop sustainable reconstruction practices for masonry and concrete structures in Haiti following the 2010 earthquake. Then Joe Maffei, Ph.D, SE, talked about lessons learned about concrete wall design from the 2010 Chile earthquake.
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A Little Fun with Testing

My apologies for being late with my blog post this week. We are having our once a year big sales meeting, so I’ve been traveling to the Midwest to participate. Speaking of traveling, several times each year, we invite our newest employees to our home office in Pleasanton, California for a week-long Sales and Product Orientation class. Although originally envisioned as detailed product knowledge training for our sales people, the class has evolved over the years to include people from all areas of our business such as finance, accounting, IT, purchasing, quality, marketing, and (of course) engineering.

I do one presentaton for the class explaining the importance of a continuous load path in a building, and another covering the history of innovation that led to some of our products. It is a great opportunity for me to meet my new coworkers by spending some time with them before they embark on their careers in different parts of the country (or world!).

My favorite training session I do for the class is about product development and testing, which includes a tour of our test lab in Pleasanton. We go over a lot of testing basics – how we select lumber, get parts made, build setups and run the tests. For a demonstration, I used to run a simple joist hanger test and also a holdown test. Usually I’ll pick a heavy holdown to test, since those make an impressive bang when the steel breaks, and then everyone jumps and gets a good laugh out of it.

Cantilever Floor Induced Load Path Concerns

IBC Section 1604.9 requires structural members, systems, components and cladding be designed to resist forces due to earthquakes and wind, with consideration of overturning, sliding and uplift. It also states that a continuous load path be provided for transmitting these forces to the foundation. Seems obvious to engineers that a continuous load path is needed, but it’s still nice to have the code say so.

But what happens if your structure’s upper and lower story walls do not stack? How do you create the required continuous load path? As engineers, we try to steer the architect towards eliminating the offset, making things line up, and keeping construction simple. But architectural requirements cannot always accommodate simple, and non-stacking walls occur all the time.

Confidence in Code Reports

Every building uses products that are not specifically covered in the building code. IBC Section 104.11 permits this if the “alternative material” is found to comply with the code intent by the building official after review of supporting information, such as research reports and tests.

Reviewing product data might be a challenge for some building departments, as they vary in size and expertise around the country. Some of the questions they might ask are:

1. What, if any, criteria was used to evaluate the product (e.g., test protocol, load rating methodology),

2. Was the criteria developed based on a single individual or a single company’s opinion or was there at least some involvement of others in the construction industry,

3. Are there any potential conflicts of interest in the parties wanting to use the product or the company who evaluated the product, and

4. Are there other tests or analyses that need to be completed prior to accepting the products use in the jurisdiction?

Corrosion in Coastal Environments

“An ounce of prevention is worth a pound of cure”

– Benjamin Franklin

Any contractor that has ever had to replace a corroded connector or fastener will tell you this quote is an understatement. Here at Simpson Strong-Tie, we spend a lot of time refining new product designs to simplify their installation, but uninstalling a joist hanger? It never crosses our minds, and it shows by looking at all the tools you would need: claw hammer, cat’s paw, reciprocating saw, and the all-important first aid kit.

But luckily for the project owner, an ounce of prevention only costs about the price of half a pound of cure. Stainless steel connectors and fasteners are in the range of 5-10 times the cost of galvanized steel. However, connections are usually only a small part of a project’s overall budget and are a critical part of the load path, so the argument for stainless steel is an easy one to make.