The UK government and building industry are doing a lot of soul-searching in the aftermath of the tragic Grenfell Tower fire in London. In certain respects, perhaps we also may need to do some soul-searching.
Presently, there are 80 confirmed fatalities from the fire, which occurred shortly after midnight on June 14.
The apparent cause of the fire was a refrigerator in a dwelling unit on the third floor of this 24-story high-rise apartment building. It is reported the fire in the dwelling unit ignited aluminum clad insulating panels on the building exterior. The fire then proceeded to extend up the building exterior, igniting fires on upper floors as it went.
You may have seen video of the event on the news. The building burned like a roman candle, similar to several recent fires in Dubai, China, Russia, the Philippines and France.
The Grenfell Tower was constructed in 1974; the building had 120 apartment units. Four years ago, the building underwent a refurbishment that included the installation of the aluminum clad insulating panels to improve the building appearance and its energy efficiency.
Early reports indicate the aluminum-clad insulation that was provided and installed contained a polyethylene core. This metal panel with the PE core was apparently substituted in place of the specified, but more costly, metal panel from the same manufacturer which had a fire-retardant mineral core.
There are conflicting reports as to whether the use of the panels with the PE core was in violation of British building fire regulations. Here are various quotes from reports on the fire which demonstrate the confusion around the question of the legality of the PE panels:
The fire has also raised concerns that fire safety may be taking a back seat to building sustainability and energy efficiency.
From “Insulating skin on high-rises has fueled fires before London,” published June 18 by Justin Pritchard of the AP: U.S. Green Building Council, said that the Grenfell tragedy holds safety lessons. “We stand with those who will learn these lessons in honest efforts to advance the aligned goals of life/safety and environmental building performance,” said Brendan Owens, an engineer and senior vice president at the council. “Compromising life/safety in search of environmental gain is not a choice.
Nice sentiments, but … In 2012, fire safety experts invited green building representatives to a symposium in Chicago. The engineers’ concern was that various green requirements could inadvertently conspire to increase fire danger. Brian Meacham, a fire protection engineering professor at Worcester Polytechnic Institute, addressed the gathering and said he did not sense much interest in fire safety within the green building industry then — or since. “I think they view it as outside of their agenda,” Meacham said. “I don’t think they’re being necessarily mean about it; I think it’s more ignorance of the issues.”
It is understandable that much of the focus of the outcry and investigation is on the PE panels.
But it is important to remember that, as with all major life-loss fires, many factors come into play.
For example, at the 2003 Station nightclub fire in Rhode Island where 100 people were killed, it was the combination of illegal use of pyrotechnics, highly combustible exposed acoustical insulation, lack of automatic sprinklers and a poorly arranged egress system that combined to make the life loss so horrific.
At Grenfell, other factors also appear to be in play. Most significantly are the fact that upper floors only had one exit stair (see the floor plan sketch), and the building did not have automatic sprinklers.
It is difficult for us in the U.S. to conceive of a residential high-rise building with a single exit from an upper floor.
Apparently, at least as late as 1974, when the Grenfell Towers was constructed, a single exit was considered adequate by British fire regulations. It would be of interest to know if it is still possible in the UK to design a high rise residential tower with a single exit stair. Given the current controversy surrounding the “principles-based” approach to UK building fire safety design, I would not be surprised if one could.
The fact that the building was not originally provided with automatic sprinklers and that sprinklers were not retrofitted into the structure can be explained, at least in part, by the British building regulations’ reliance on passive fire protection over active fire protection. Passive fire protection revolves around the concept of containing the fire through compartmentation using such passive measures as fire barriers, fire doors, firestopping and fire dampers. Active fire protection measures would, of course, include automatic sprinklers and fire alarm and detection systems.
In a June 29 column on Salon.com, “Could a tragedy like the Grenfell Tower fire happen in the U.S.?” Professor Meacham states, “However, the concept (compartmentation) only works when the initial fire is contained. That didn’t happen at Grenfell Tower. Once the fire reached the external cladding, it spread rapidly. If the building’s residents had their windows open for ventilation, the fire could have spread even faster. The heat just outside could have ignited drapes or other items near the windows.”
So, could a Grenfell Tower like incident occur in the U.S.? Of course, it is possible but the following experts agree that is it not likely.
From his Salon.com column, Professor Meacham writes: In the U.S., most fire codes limit the use of combustible exterior cladding material, particularly on highrise buildings. The requirements for automatic sprinklers and at least two escape routes from every floor add depth to these defenses. Together, these rules increase the chance that a small fire will be put out quickly, reduce its ability to spread up the side of the building, and help people get out if they need to.
From the Daily Caller on June 17th Robert Solomon, assistant vice president for Building and Life Safety Codes at NFPA: I don’t see this happening in the U.S. We actually apply a very constrictive and restrictive test protocol to those types of systems (exterior metal clad insulating panels) on buildings. There’s not a comparable system applied to the cladding in the U.K.
The referred to strict requirements for these metal plans are from NFPA 285: Standard Fire Test Method for Evaluation of Fire Propagation Characteristics of Exterior Non-Load-Bearing Wall Assemblies Containing Combustible Components. Both the International Building Code and NFPA 5000 require materials to comply with NFPA 285 in buildings over 40 feet in height above grade. The Grenfell Tower was about 220 feet in height.
The Grenfell Tower fire exemplifies many of the issues of concern to the building construction industry. I think these would include:
We may feel safe in the thought that a similar event is not likely to occur in the U.S. Still building industry professionals in the vanguard of building fire safety in the U.S. should not be lured into complacency. We too need to do some soul-searching. l