The TRB Committee Code Change Proposals

By Richard Schulte

The investigation into the collapse of the World Trade Center towers by the National Institute of Technology (NIST) began in August of 2002, and NIST delivered its final report on its investigation to the Congressional Science Committee on October 26, 2005. Included in NIST's final report were 30 recommendations for making buildings, in particular, high-rise buildings, "safer."

After NIST issued preliminary reports on the WTC investigation in the spring and early summer of 2005, technical committees formed by the International Code Council (ICC) and the National Fire Protection Association (NFPA) began to study the findings and recommendations included in the report. The ICC assigned the task of reviewing the NIST findings and recommendations to the Ad Hoc Committee on Terrorism Resistant Buildings (AHC-TRB). In the spring of this year, the TRB committee developed and submitted 14 code change proposals to be included in ICC's 2006/2007 code development cycle (which will result in the 2007 supplement to the 2006 codes).

The hearings that will consider the TRB's code change proposals, as well as more than one thousand other code change proposals, will be held in Lake Buena Vista, Florida, in late September (2006); the final code change hearing that will consider these proposals will be held in late May 2007. Given that the code change proposals developed by the TRB committee will have a substantial impact on the cost of constructing new buildings, particularly new high-rise buildings, a review of the TRB's proposals is in order. The 14 code changes proposed by the TRB committee are as follows:

Code Change Proposal G7 (IBC). This proposal will require that video cameras be provided in exit stair enclosures, in elevator lobbies, in elevator equipment rooms and at the top of elevator hoistways of all high-rise buildings. The International Building Code (IBC) defines a high-rise building as a building that has (normally) occupied floors located more than 75 feet above the elevation of the lowest level of fire department vehicles in the vicinity of the building. In addition, this proposal will also require temperature sensors in elevator equipment rooms in high-rise buildings. Video display equipment will be required to be provided in the command center required in high-rise buildings so that emergency responders can monitor the video feed from the required cameras.

Code Change Proposal G68 (IBC). This proposal will require that the minimum required bond strength for spray-applied fireproofing materials used to protect steel structural members in high-rise buildings be increased from 150 psf to 430 psf for high-rise buildings with a height up to 420 feet and from 150 psf to 1,000 psf for high-rise buildings greater than 420 feet in height.

Code Change Proposal G69 (IBC). This proposal will require that all buildings greater than 420 feet in height be designed to prevent building collapse when subjected to a fire that spreads throughout the entire building. (This proposal, of course, assumes the failure of the sprinkler system protecting the building.)

Code Change Proposal G71 (IBC). This proposal will require that an additional exit stair be provided in all high-rise buildings (except apartment buildings) exceeding 420 feet in height.

Code Change Proposal G72 (IBC). This proposal will require that exit stairs serving high-rise buildings be located one-half of the diagonal distance of the floor apart, rather than one-third of the diagonal distance of the floor apart, where only two exit stairs are provided in the building. (Buildings less than 420 feet in height and apartment buildings exceeding 420 feet in height will be permitted to be served by only two exit stairs.)

Code Change Proposal G73 (IBC). This proposal will require that exit stair enclosures in buildings that exceed 420 feet in height be enclosed using wall construction capable of resisting a minimum static load of two pounds per square inch (psi).

Code Change Proposal FS100 (IBC). This proposal will add new code text that will indicate that spray-applied fireproofing materials are required to be installed in accordance with the listing requirements for the fireproofing material. This proposal will also add code text that addresses the use of spray-applied fireproofing materials on structural steel members that have been coated with primers and/or painted.

Code Change Proposal FS135 (IBC). This proposal will require that projections into the headroom clearance that do not comply with code requirements be marked with striped markings.

Code Change Proposal E84 (IBC). This proposal will require that stair treads, stair landings and stair handrails in high-rise office, school, mercantile and hotel buildings be provided with photo-luminescent markings.

Code Change Proposal E137 (IBC). This proposal will require that exit stairs serving all buildings be vertically aligned throughout the height of the building. In other words, horizontal offsets in the exit stairs would be prohibited, except at the grade floor of a building.

Code Change Proposal F220 (IBC/IFC). This proposal addresses the issue of fuel storage and fuel piping provided for electric generators located in high-rise buildings. The proposal will permit fuel storage in excess of the exempt quantities of hazardous materials in high-rise buildings, provided that the storage complies with the requirements outlined in the proposal.
[Note] IFC refers to the International Fire Code.

Code Change Proposal F221 (IBC/IFC). This proposal addresses the design of sprinkler systems protecting high-rise buildings that exceed 420 feet in height. The proposal will require that sprinklers be supplied by connections to two different sprinkler risers, require additional control valves in sprinkler risers and require pumps to be supplied by a minimum of two connections to the municipal water distribution system on different streets.

Code Change Proposal S5 (IBC). This proposal will establish design criteria to address the issue of disproportionate collapse. The proposal is based upon disproportionate collapse provisions presently used in Britain.

Code Change Proposal S38 (IBC). This proposal addresses the requirements for special inspections of fireproofing materials applied to structural steel members and metal floor and roof decks. This proposal will increase the number of tests required for fireproofing materials.

General Analysis
The Congressional Science Committee held its first hearing on the collapse of the World Trade Center towers on March 6, 2002. This hearing commenced with a statement by the chairman of the Science Committee, Congressman Sherwood Boehlert. Excerpts from Congressman Boehlert's statement include the following:

"The Committee decided to move forward for two fundamental reasons. First, we believe that we owe it to the victims and their families to learn everything possible about what happened in those horrifying first hours of September 11 - not just to satisfy their immediate needs and yearnings, but to ensure that such a catastrophic building failure, and the resulting loss of life, never happen again."

"Another significant lesson of the Trade Center collapse is that we need to understand a lot more about the behavior of skyscrapers and about fire, if we are going to prevent future tragedies."

"But this hearing is not so much about the past as it is about ensuring that we protect lives in the future."

Among the witnesses who testified at the hearing was Dr. Arden L. Bement Jr., the director of NIST at the time. Excerpts from Dr. Bement's testimony included the following:

"... to study procedures and practices used to provide adequate structural reserve capacity to resist abnormal loads (e.g. blast, explosion, impact due to aircraft or flying debris from tornadoes, accidental fires, and faulty design and construction), especially those that can be anticipated prior to construction (e.g. impact of a Boeing 707) ..."

"Yet, the United States has not developed standards, codes, and practices to assess and reduce this vulnerability. Adding to the problem for modern structures is their smaller margin of safety - and the reserve capacity to accommodate abnormal loads - due to increased efficiency in the use of building materials and refinements in analysis techniques ..."

"The overwhelming majority of buildings in public use today are vulnerable to terrorist attack on a number of fronts ..."

"The final program element supports a construction-industry-led roadmapping effort to reflect changed priorities for development and deployment of safety and security standards, technology, and practices."

"The effort would complement and support parallel efforts of technical organizations to improve standards, codes, and practices."

"In conclusion, I believe it is imperative for the United States to learn from the worst-ever building disasters in human history and to take aggressive remedial action to minimize future losses."

As evidenced by Dr. Bement's testimony in March 2002, NIST clearly had in mind developing design and construction standards for "terrorist-proof" buildings when it began its investigation into the collapse of the World Trade Center towers. At some time during its investigation, the NIST investigators began to realize that designing and constructing buildings to be "terrorist-proof," or even "terrorist-resistant," simply isn't feasible. Dr. Shyam Sunder, the lead investigator for the NIST WTC investigation, indicated that the NIST recommendations did not (and would not) address the issue of terrorism in his presentation on May 20, 2005, at a meeting of the American Institute of Architects (AIA) held in Las Vegas. On June 8, 2005, Dr. Sunder again indicated that the NIST recommendations would not address terrorism in a presentation at the annual meeting of the National Fire Protection Association, also in Las Vegas.

In the middle of September 2005, NIST held a two and one-half day technical conference on its investigation into the collapse of the World Trade Center towers at its headquarters in Gaithersburg, Maryland. During the presentations at the conference, there was no discussion of making buildings "terrorist-proof," or even "terrorist-resistant." In the final 30 minutes of the conference, Dr. Sunder discussed NIST's rationale for its recommendations. Dr. Sunder stated that it was NIST's opinion that high-rise buildings should be designed and constructed to address multiple simultaneous hazards, i.e. a building fire occurring as a result of or during hurricane force winds or winds from a tornado. For some (unexplained) reason, NIST did not include the rationale for its recommendations in its 10,000-page investigation report. Hence, unless you attended the NIST technical conference in September 2005 or the AIA or NFPA meetings in Las Vegas in the spring of 2005 (or read this column or ENR magazine), you would probably not be aware that the NIST recommendations were not intended to address the issue of terrorism.

Even though the rationale for NIST's recommendations was not clearly elaborated in the investigation report, one would expect that a committee assigned to study the NIST recommendations would have recognized and been aware that those recommendations are not intended to address the issue of "terrorist-resistant" building design. Given this, it is unclear why the Terrorism Resistant Buildings committee utilized the NIST recommendations as a basis for any of the code change proposals that the committee developed.

Specific Analysis
Code Change G7. The supporting statement for this code change indicates that "the purpose of this change is to increase the ability of firefighters and other emergency responders to develop a clear picture of conditions throughout the building that will enable them to better manage evacuation, fire suppression and other emergency response activities." While providing the capability to better manage a building evacuation would seem to be a reasonable proposal, the supporting statement for this proposal does not establish that there is presently a problem that is in need of being addressed. Just how many times in the last 30 years has there actually been a problem with evacuating a high-rise building protected by a sprinkler system in the United States, and will there be sufficient emergency personnel available to actually utilize the information that would be provided by the video cameras?

The answer to the first question is that a full evacuation of a high-rise building protected throughout by a sprinkler system has never occurred, except as a result of a terrorist attack. Would video cameras in the proposed locations have made a difference had cameras been provided in the World Trade Center towers on September 11? The answer to this question is "highly unlikely," assuming, of course, that the video transmission would even have survived the initial aircraft impacts.

As to the question of whether or not there will be sufficient personnel available to utilize the information provided by the video transmissions, one has only to study the response of the Chicago Fire Department to a relatively small fire at the Cook County Administration Building on Oct. 17, 2003. Although this fire was confined to a single tenant space that was roughly 3,000 square feet in floor area, the Chicago Fire Department, one of the largest fire departments in the United States, was unable to utilize information that building occupants were trapped in the stairs above where firefighting operations were being conducted. This failure to use available information resulted in the death of six occupants of the building (and will certainly result in large judgments against the City of Chicago in the lawsuits filed by the relatives of the victims).

Would video cameras in the stairs have assisted the Chicago Fire Department in locating the victims prior to their deaths? Unlikely, since the stair in which the victims were found was filled with both heat and smoke, due to the fact that the stair door on the fire floor was opened so hose lines could be advanced through the door. Will the video cameras continue to function at elevated temperatures often found in stairs (in the event of sprinkler system failure) and will the video cameras provide any useful information when obscured by smoke? If the sprinkler system functions properly, there will be no need for the video cameras (in the event of a fire) because only a minimal evacuation will be required, and, if the sprinkler system fails, it is questionable whether the video cameras will provide any useful information.

Code Change G68. The code change proposal to increase the bond strength of fireproofing materials used to protect structural steel members in high-rise buildings is obviously a direct response to the collapse of the World Trade Center towers. The supporting statement for this proposal relies on the fact that NIST recommended that the bond strength of fireproofing materials be increased. It should be noted, however, that neither the NIST report nor the supporting statement for this proposal identifies a problem with fireproofing materials with a bond strength of 150 psf. Neither NIST or the TRB committee can point to a collapse of a steel-framed high-rise building in the United States exposed to fire, other than on September 11.

We do know that the First Interstate Bank Building in Los Angeles and the One Meridian Plaza Building in Philadelphia were both steel-framed high-rise office buildings protected by low-density sprayed-applied fireproofing materials. (Low-density fireproofing materials have a bond strength that complies with the 150-psf requirement.) The First Interstate Bank Building survived a burnout on four floors and a partial burnout of a fifth floor in a fire on May 4 and 5, 1988. The One Meridian Plaza Building survived a burnout of eight floors in a fire on February 23 and 24, 1991. Neither building suffered even a partial collapse of any portion of the building structure; the First Interstate Bank Building reopened four months after the fire. (While the structural fireproofing for the One Meridian Plaza Building performed its intended function, the building was structurally unstable after the fire exposure and was eventually demolished).

This code change proposal, in effect, implies that low-density fireproofing materials are defective products. If this is the case, why is the scope of this proposal limited to high-rise buildings? And why hasn't a companion change been proposed to require the retroactive replacement of all existing low-density fireproofing material installations with either medium-density or high-density fireproofing materials? The fact is that the adequacy of low-density fireproofing materials has been demonstrated over the last 30 years, and the TRB proposal provides no evidence to the contrary.

Code Change Proposal G69. The code change proposal which will require a "performance analysis" to demonstrate that a building design is capable of withstanding a total "burnout" without local collapse also appears to be in direct response to the collapse of the World Trade Center towers. It is interesting to note that even if the World Trade Center towers and the 7 WTC Building had been designed to comply with this proposal, the collapse of the towers and the 7 WTC Building would not have been prevented because this proposal only addresses the normal or typical conditions of occupancy. In other words, this proposal does not address missile attacks on a building or fires fueled by diesel fuel being pumped into the fire.

Given the performance of both the First Interstate Bank Building and the One Meridian Plaza Building, it would appear that structural fire resistance ratings presently required by the International Building Code are more than adequate to prevent both collapse of the entire building and also local collapse. (For more commentary on structural fire resistance requirements for high-rise buildings, see the supporting statement for code change proposal G59-06/07.)

In addition to the above, it should also be noted that the performance structural analysis under fire conditions mandated by this requirement is in its infancy. NIST's structural analysis of the WTC towers collapse under the fire conditions took almost two years to conduct, required simplifications of the structural model of the towers (to reduce the time it took to run the computer analysis of the structure) and cost millions of dollars. Given the fact that no steel-framed high-rise building has ever collapsed under normal fire conditions, the benefits of the analysis mandated by this proposal certainly seem questionable.

Code Change Proposal G71. The code change that will require high-rise buildings with a height exceeding 420 feet (except apartment buildings) to be provided with a minimum of three stairs is yet another proposal that is obviously in direct response to the collapse of the WTC towers. The supporting statement for this proposal indicates that "this proposed change is intended to enable rapid full evacuation of very tall buildings by ensuring that ongoing and critical firefighting activity does not reduce the total required exit capacity needed to evacuate the remaining occupants of the building."

The supporting statement for this proposal further indicates that "sound high-rise firefighting doctrine provides that the fire department take control of one stair, the one most appropriate to the circumstances of the given fire condition, in order to conduct suppression activities." The supporting statement also indicates that "the principal purpose of this change is to maintain egress capacity in the case of fire events, but the additional stair will also significantly shorten the time needed for full evacuation in non-fire events."

While the supporting statement amply explains the purpose for this change, no explanation for the reason or examples of why an additional stair should be required in sprinklered high-rise buildings has been provided by the TRB committee. The missile attacks on the WTC towers clearly demonstrated that, under conditions far worse than those anticipated by this proposal, the minimum egress width required by the code will provide more than adequate egress capacity for buildings taller than 420 feet in height. These two examples of full and complete evacuations under the nightmarish conditions of September 11, coupled with the magnificent fire safety record of high-rise buildings protected throughout by a sprinkler system over the last 30 years seem to call into question the need for an additional stair. The "sound high-rise firefighting doctrine" alluded to in the supporting statement is for buildings that are not protected throughout by a sprinkler system. The TRB committee has yet to cite even one example of a major fire occurring in a sprinklered building where an additional stair would have contributed to the safety of the occupants of the building. (A major fire has never occurred in a high-rise building protected throughout by a sprinkler system, other than on September 11.) Clearly, the TRB committee has confused the firefighting tactics for unsprinklered high-rise buildings with the tactics required for sprinklered buildings.

Code Change Proposal G72. The code change requiring exit stairs serving high-rise buildings to be located further apart is another example of a reaction to the events of September 11. Again, the only incident that the TRB committee (or NIST) can cite where the location of exits with respect to one another has been a problem in high-rise buildings protected by a sprinkler system is missile attacks on the WTC towers. Throughout the supporting statements for code changes proposed by the TRB, it has been stated that these proposals are not intended to address an incident similar to the attacks on the towers. If this is actually the case, then clearly this proposal is a solution to a problem that simply doesn't exist in sprinklered high-rise buildings.

Code Change Proposal G73. The code change proposal to require exit stair enclosures to be designed and constructed to be capable of resisting a static load of two pounds per square inch again appears to be a direct response to the September 11 incident. However, this proposal also ignores the fire record of high-rise buildings. If the use of gypsum wallboard to enclose exit stairs is actually a problem, the TRB committee should have been able to cite one example, other than the WTC towers, of where gypsum enclosures failed to protect the stairs due to a lack of "robustness" of the material.

Based upon the fire record, maintaining the integrity of stair enclosures has little to do with the material used for the enclosure. The FEMA investigation report on the fire that occurred at the One Meridian Plaza Building indicates that the exit stairs in this building were enclosed using concrete masonry. The fire investigation report also indicates that the exit stairs were filled with smoke prior to the arrival of the Philadelphia Fire Department at the scene. The reason for the failure of the stair enclosures cited in the FEMA report was unprotected penetrations of the enclosure.

A failure of poured concrete exit stair enclosures also occurred at the fire in the Cook County Administration Building. The reason for the failure of the concrete enclosures was that the Chicago Fire Department opened the door to the fire floor in order to advance hose lines, allowing both heat and smoke into the enclosure. Of course, in any large fire in a high-rise building, the fire department will eventually have to open the stair doors to gain access to the fire floor and, when that happens, the stairs will fill with both smoke and heat. (Again, it must be noted that a large fire has never occurred in a high-rise building protected throughout by a sprinkler system.)

How much additional protection will compliance with this proposal provide for the exit stairs? The TRB committee's supporting statement doesn't provide an answer to this question.

Code Change Proposal FS100. This proposal simply "parrots" the requirements for the listing of spray-applied fireproofing materials. Is it necessary for the code to indicate that the application of fireproofing materials should be in accordance with the manufacturer's instructions and listing requirements? If a contractor involved in the business of applying spray-applied fireproofing isn't already familiar with the manufacturer's instructions for applying the materials, it is highly unlikely that the contractor will become familiar with the instructions simply as a result of this proposal.

Code Change Proposal FS135. No further comment is required for this proposal. The proposal addresses low headroom clearance not permitted by other provisions contained in the code. In effect, this proposal is a remedy for a code violation.

Code Change Proposal E84. This proposal appears to have been developed to address the "problems" that occupants have in using the stairs during an evacuation of high-rise buildings. However, the supporting statement for this proposal provides no evidence that compliance with the proposed requirements will actually be of any assistance in an evacuation. The supporting statement for the proposal also does not provide an explanation of why this stair marking is only necessary in high-rise buildings. In the absence of any substantiation, this proposal simply appears to be TRB's opinion regarding what may be helpful in an evacuation.

Code Change Proposal E137. The proposal that exit stairs be designed and constructed without offsets is another proposal that was clearly developed as a reaction to the attacks on the WTC towers. The requirements contained in this proposal are neither necessary nor practical. "This issue of confusion of occupants evacuating a building caused by offsets in stairs can easily be addressed by signage in the stair enclosure and by conducting evacuation drills. Offsets in stair enclosures are simply a necessity for the efficient use of high-rise buildings."

Code Change Proposal F220. This proposal is again a response to the events of September 11, in particular to the suspected reason for the collapse of the 7 WTC Building. This proposal seems to address a rare design where flammable/combustible liquids are pumped from storage tanks to a generator located on another floor.

Code Change Proposal F221. This proposal is an attempt at making sprinkler system installations in high-rise buildings more reliable. The assumption of this proposal is, of course, that the reliability of sprinkler systems protecting high-rise buildings is suspect and is in need of improvement. Given that there has never been a major fire in a high-rise building protected throughout by a sprinkler system, this assumption appears to be erroneous.

Rather than adopt the recommendations of the TRB committee, it would seem that it would be more appropriate to refer this issue to the NFPA committees on sprinkler and standpipe system installations.

Code Change Proposal S5. Like many of the other TRB proposals, this proposal has been spawned by the collapse of the WTC towers. Given this, it would be logical to conclude that the collapse of the WTC towers was a disproportionate collapse, but the towers collapse was anything but disproportionate. Given the damage done to the towers by the aircraft impact, followed immediately by simultaneous fires on multiple floors, both towers performed magnificently. Most buildings would have collapsed immediately after aircraft impact, yet the towers withstood the impact and fires long enough to allow 99 percent of the occupants below the floors of impact to escape.

Would compliance with the disproportionate collapse provisions proposed by the TRB have affected the outcome of the attack on the WTC towers? Absolutely not. The TRB proposal only addresses the failure of a single vertical member.

The supporting statement for this proposal indicates that "incredible as it may seem, our codes and standards do not in any way prohibit a structural system that is, literally, the proverbial 'house of cards.'" Given this, you would think that the TRB committee would have included a long list of buildings that suffered disproportionate collapse, but the supporting statement does not include a single example of disproportionate collapse. The reason for this should be obvious - disproportionate collapse is indeed a rare event.

Code Change Proposal S38. The fourteenth proposal submitted by the TRB, which proposes an increased level of testing and inspection for spray-applied fireproofing materials for structural steel members, is perhaps the only proposal by the TRB that could be described as logical. That being said, it remains to be seen whether or not the increased level of testing and inspections will actually result in improved fireproofing installations.

My personal experience with special inspections of spray-applied fireproofing (when I was with the San Jose Fire Department) indicate that inspections of fireproofing are only as good as the inspector performing the inspections and tests. In my opinion, the maintenance of the fireproofing is at least as important, if not more important, than the initial installation of the fireproofing.

Conclusion
The fact that the TRB committee did not recognize that the NIST recommendations were not intended to address terrorism "casts a long shadow" over the TRB committee's package of proposals. When the supporting statements for the TRB's code changes are reviewed, it can be seen that the TRB's principal rationale in support of their proposals is the NIST recommendations. Unfortunately the final report on the NIST WTC investigation does not include any substantiation for NIST's recommendations, hence the TRB committee's proposals are, far the most part, unsubstantiated. Should unsubstantiated proposals be included in the building code used throughout most of the United States? Just my opinion, but including unsubstantiated proposals in the building code makes a mockery of the code.

 

Richard Schulte is a 1976 graduate of the fire protection engineering program at the Illinois Institute of Technology. After working in various positions within the fire protection field, he formed Schulte & Associates in 1988. His consulting experience includes work on the Sears Tower and numerous other notable structures. He has also acted as an expert witness in the litigation involving the fire at the New Orleans Distribution Center. He can be contacted by sending e-mail to rschulte@plumbingengineer.com.