For anyone following the cover building industry, you are likely aware that a Fabric Covered Building owned by the Dallas Cowboys blew down in May of 2009. (If you are interested in learning more about this incident, please click here.) This was not an Accu-Steel building that collapsed, but many people have asked us about how our products differ from the manufacturer of that building. Our intention in posting this information is to inform current and potential customers about how the workmanship and engineering in our products differ from that and other competitors.
The National Institute of Standards and Technology (NIST) issued a draft report about the events on May 2, 2009 that led to the building collapse. You can review the entire document by clicking here and a presentation highlighting the findings by clicking here. The findings and recommendations are on page 81 (Chapter 6) of the entire document are summarized below.
The Canadian-based manufacturer said it was adhering to local building codes and had designed the building to withstand 90 mph winds. The NIST report states, “the wind speed at the time and location of the collapse was in the range of 55 mph to 65 mph.”
The report lists four factors that were "primary contributors to the collapse of the structure":
1. Wind-load calculations were faulty, both in the original 2003 design and in 2008 reinforcements.
2. The steel framing was not as strong as the manufacturer calculated in 2003.
3. The original design did not consider potential joint weaknesses.
4. The 2008 reinforcements "had a minimal effect," and "the most critical members were not reinforced."
Most Accu-Steel competitors (including the one in the collapse) include “Tension Membrane Analysis” in their engineering. This means that if the tension is lost in the fabric, the building is no longer stable. Accu-Steel does not include this analysis in our engineering; this typically results in Accu-Steel having more steel and cabling in the building and results in a building that is structurally sound even without a cover.
The NIST made the following recommendations to the Fabric Cover Industry. We welcome them as this is how we have been doing business for the past 10 years.
A. Re-consider the use of fabric tension analysis. Ensure that the structure will still be stable in the event of debris tearing the fabric and removing the lateral building strength.
B. Given the nature of the buildings, they should not be considered “fully enclosed structures.”
(Considering a building “fully enclosed” or “partially enclosed” changes the engineering requirements. The NIST recommendation for no “fully enclosed structures” is how Accu-Steel considers all of our buildings)
C. There needs to be a way to change the bracing in buildings when the engineering included tension membrane analysis. The NIST asks manufacturers to put in retro-fits to strengthen the buildings with Tension Membrane Analysis. Since Accu-Steel does not include this in the engineering, no retro-fit is required in any of our buildings.
Any Accu-Steel building should meet or exceed the local codes. We’ll report back when the final recommendation comes out as to any changes to expect.
Bottom Line here: There is a price to pay for a “Cheaper” building. We will not compromise on safety or quality, where others will. Solid engineering practices, integrity and a focus on long-term customer value will continue to drive our business forward.
If you have any questions or would like more detailed information about our products and services, please contact us.
