All Things Gypsum
Keeping Events Grounded in Reality
Numerous research papers and reports have been issued detailing specific aspects of the collapse of the World Trade Center towers and the damage inflicted on the Pentagon. Most of the reports are available to the general public and many are posted in electronic format on the Internet.
The analysis in the reports is generally thorough and, often to a mind-numbing degree, methodical; however, it all begs one to ask a simple question: Why bother? If we know the basic cause of the WTC collapses and the damage to the Pentagon (the impact of jet airplanes), and we know the effects generated by the causal acts (structural damage and, in the case of the WTC towers, collapse), what is to be gained by studying these events? And since we know that the cause of the damage was a series of coordinated attacks, why examine the effect of events (the attacks) that are seemingly random and, in the eyes of some, unpreventable? Why revisit the horror?
One possible answer is quite straightforward: The analysis process allows the examination of unique events that may have important life safety applications in other areas. Quite simply, examination requires the analysis of the specific and unique circumstances that were directly created by the attacks. If examined properly and reported fairly, conclusions drawn from the exercise may have helpful implications across a wider spectrum.
For instance, some of the immediate conjecture about the WTC attacks focused on the role that unconsumed jet fuel played in feeding the fires that occurred in both towers. For a period of time, it was generally assumed that the intense heat of the fires was produced almost exclusively by the burning jet fuel that was distributed into the buildings upon the impact of the jet airplanes. Subsequent analysis, however, has led some examiners to the conclusion that common office furnishings-items as mundane as copier paper and furniture-were ignited by the initial explosions and contributed significantly to the intensity of the fires by adding to the overall fuel load.
This may be a profound deduction because while building equipment and furnishings are typically regulated by their flame-spread rating and their ability to ignite, little attention has been paid to their possible role as fuel for a fire.
As painful as the process may be, examining the relevant evidence may save lives in future building fires. That course of action, therefore, is beneficial to any individual or organization involved in life safety issues.
On the other hand, a contrasting argument can be made. The reports do not follow a standard format, there is no agreed upon universal content, nor is there a recognized review organization available to validate the methods or conclusions found in the reports. Consequently, the unfortunate potential exists for misrepresentation of data and the skewing of conclusions both within and outside of the reports by people or organizations promoting their own agendas.
This second circumstance is especially troubling. Reports and papers created during the past two and one-half years are being used to cast the gypsum board industry in an unfavorable light. Specifically, claims have been made that since the WTC buildings were built with walls incorporating gypsum board, "more durable wall systems would have improved chances for survival for occupants above the level of impact"; and "[f]uture research should be devoted to evaluating and developing durable, fire-rated egress enclosures for high-rise buildings."
Statements such as these have appeared in articles published by organizations competitive to the gypsum industry. They are intended to create doubt about the integrity and functionality of gypsum board systems, such as those used to enclose elevator and stair shafts at the WTC.
The statements are troubling and unfounded for many reasons, specifically:
They assume that wall systems constructed from materials other than gypsum board would have survived the WTC attacks. It is preposterous to assume that any traditional building system would have been able to endure the forces placed on the WTC towers. The jet airplanes that hit the towers destroyed everything in the areas of impact and created a shock that no conventional building system could withstand.
This is not a self-serving gypsum industry response. In an article where statements railing against gypsum board systems are published, the author of record admits that "it is presumptuous to assume that [other material] enclosures would have survived the attacks"-a statement that is conveniently ignored further in the same article when the same author suggests that "more durable systems" (i.e. non-gypsum systems) "would have improved chances for survival for occupants."
They ignore the concept that constructing the towers was facilitated by the use of gypsum board shaft wall systems. Light in weight and able to withstand the pressure exerted by high-speed elevator systems, gypsum board shaft wall systems, revolutionary in design for the period in which the WTC was constructed, were perfect for the tower project. Had they not been incorporated into the overall design, it is highly unlikely that the WTC towers would have been built to their finished height or achieved their finished dimensions. Other, more traditional, materials would have required thicker floor slabs and deeper footings due to their excessive weight. Simply stated, without the gypsum systems, the WTC would not have existed in the form in which we knew it.
They assume that increased wall durability translates to increased occupant safety. Durability is a difficult concept to define. Standards creation organizations have debated the concept of system durability for decades without much resolution. What typically causes the impasse are two issues: "How durable is durable enough?" and "Does durability really translate into increased life safety?" To date, neither question has been answered.
Gypsum board systems are durable. The shafts at the WTC performed unfailingly for more than 30 years. How much more durable does something need to be? In addition, how would a "more durable design"-whatever that might mean-have actually saved lives at the WTC? The shafts and stairs would not have survived the impact of the jet airplanes regardless of the material used for construction, so what exactly would have been accomplished by a "more durable" system?
They request a design for the aberration, not the norm. Making every above-ground building a fortress might make it less susceptible to damage from an attack; however, one must ask whether it truly accomplishes anything beyond that. Requiring all high-rise structures to be "vertical bunkers" would place severe limits on the ability to design and construct a high-rise building, and it would ignore the interests of the real estate and development industries. Essentially, it would eliminate high-rise design, as we currently know it, for cost reasons.
The gypsum board manufacturing industry has always been (and always will be) supportive of efforts to improve life safety in buildings regardless of the type of occupancy or the type of structure; however, mandating that structures be constructed using specific materials to satisfy unproven requirements is not economically sensible, nor is it in the best interest of the public. Creating buildings that are required to incorporate heavy, solid materials won't necessarily make them any safer; all it will do is make them shorter in height and more expensive to construct.