Grenfell BRE Report: If Code Followed, Likely Wouldn't Have Happened
A Building Research Establishment (BRE) report summarizing the investigation into the deadly Grenfell Tower fire last year in London has been leaked, and several causes for the tragedy were identified. Each of the following excerpts from the report are linked to the online report. Each of the BRE excerpted report pages are also linked at the end of this article.
The report states that Grenfell Tower as originally constructed provided “very high levels of passive fire protection,” but that a refurbishment undertaken between 2014 and 2016 was not performed correctly, and opened multiple avenues for fire spread, in the event of an accidental fire.
Essentially, the report makes clear that had the refurbishment been completed to code, it is highly unlikely the fire would have spread beyond the original flat nor would there have been any loss of life.
Building code requirements in the United States are comparable, if not more exacting, than those that applied to the construction of Grenfell Tower. It is clear from the report’s conclusions that enforcement of the code is the most effective way to prevent similar occurrences both in the U.S. and U.K. To understand why, it’s vital to look at the conditions that led to the rapid fire spread.
Between 2014 and 2016, Grenfell Tower received a new cladding and insulation system as part of a refurbishment. The BRE report notes that both the insulation and the aluminum composite panels used provided combustible fuel for the fire. These materials have been used successfully for many years, and when installed in a code-compliant manner, are properly separated from living spaces and use detailing to prevent the spread of the fire inside the wall to the next higher floor.
In the case of the Grenfell Tower refurbishment, however, key details were ignored which allowed the fire to reach the cladding, and once there, to spread without check. New windows were installed in a way that “lacked any barriers to fire spread between flats and the cladding system” and cavity barriers in the cladding system meant to expand to block off the cavity during a fire were too small to expand fully, and in many cases, improperly installed.
These shortcomings allowed the fire to easily move from interior living space to the exterior façade (and vice versa), and spread quickly across the façade.
Fortunately, when buildings similar to Grenfell Tower are constructed in the U.S., they are subject to the International Building Code (IBC). The International Building Code (IBC) directs builders and designers through a series of questions when it comes to cladding exterior wall systems. These questions include:
- What is the building occupancy? IBC Chapter 3.
- What type of building is it? IBC Chapter 6.
- What is the building’s height and area? IBC Chapter 5.
- How close is the building to other buildings? IBC Chapter 6.
- Will it have a sprinkler system? IBC Chapter 9, Chapter 14.
- Does it need to meet the NFPA 285 test standard? IBC Chapter 14, Chapter 15, and Chapter 26.
With limited exceptions for some one-story buildings, Chapter 26 of the IBC requires buildings of type I-IV construction of any height which contain foam plastic insulation to comply with National Fire Protection Agency standard 285 (NFPA 285). To comply, testing and professional engineering analysis are performed where the proposed wall and cladding system is subjected to fire exiting from a window (as happened with the Grenfell Tower). To pass, fire tests and related professional engineering analysis must show that fire spread vertically or horizontally along the cladding beyond the immediate area is less than the time it would take for the inhabitants to evacuate (i.e. the NFPA measurement of this concept is ten feet of vertical and five feet of horizontal flame spread away from the window opening during the 30 minute test.)
The IBC also requires all high rise buildings to include an automatic sprinkler system. The BRE report states that had a sprinkler system been installed in the Grenfell Tower, it “could have significantly altered the outcome of the fire” by putting out the fire before it left the original apartment.
Given the report’s conclusions regarding the construction detailing and the resulting spread of fire in the Grenfell Tower event, a key questions is: “Does this event reflect expected fire resistance performance, in code compliant construction, in a way that should cause significant regulatory changes for U.S. buildings?”
It seems clear from all the information available, if designers, builders and installers perform in a manner that conforms with the requirements of the IBC, the 30 years of demonstrated effective and safe performance, when using NFPA 285 and IBC Chapter 26, will continue.
For more in depth information on fire safety and the use of foam sheathing, read this recent document created by the American Chemistry Council’s Foam Sheathing Committee (FSC).
For additional information about this topic please review:
- Understanding Fire Safety and the Use of Foam Sheathing
- ICC Provides Perspective on Combustible 'Cladding Systems'
- Post Grenfell, Do You Know the Code and Your Cladding Options?
- Would Smoke Alarms and Sprinklers Have Saved Grenfell's Installed Cladding?
- London's Grenfell Fire: Will Plastics Be Inappropriately Blamed?
Here are links to the 13 leaked pages from the Draft BRE Report: