The fire protection conundrum
Recent events involving high-rise structures around the world, and the inevitable questions these have raised about building regulations, fire testing of materials, materials specification and the installation of partitions, cladding systems, fire doors and several other matters to do with fire protection reminded me of the plaque I used to have on the wall in my office. It read; “Experience is what helps me make a different mistake the next time.”
However, experience must be informed by knowledge, and that must then inform the lessons one draws from it. The designer, the construction engineer, the installer and the end user all need to fully understand what the fire protection is, how it will work and what could cause it to fail. That is a major challenge.
I was a young fireman when the Andraus building caught fire in 1972 in Sao Paulo and killed sixteen, injuring some three hundred more. Just two years later, the Joelma building burned in the same city killing 179 with another 300 injured. “Lessons were learned” as the saying is, and all over the world changes were made to building regulation requirements for such high-rise buildings. Requirements covering fixed fire fighting systems, multiple escape routes, adequate fire stopping and the use of combustible partition systems, ceilings and linings were introduced. Since then there have been many more, the most recent involving combustible cladding systems. Innovation in design and greatly increased height of structures, introduce new challenges for fire protection. Increased insulation, increased use of synthetic materials in finishes and fittings, and in furniture all mean greater fire loads within the building.
Adequate fire protection involves a matrix of systems, materials, application, use and maintenance. Following the fires in Lakanal House (2009) and Grenfell Tower (2017) questions have been asked about the use of certain materials and their suitability. There is a great deal of misunderstanding about the behaviour of any material in a fire test, and its behaviour in the real world in combination with several others. Many believe that a Fire Test Certificate is a guarantee that a material is suitable and safe for use. As those running these tests will tell you – and as dramatically demonstrated in the full scale tests done at Cardington following the Stardust Disco fire (Dublin, 1981) – none of the standard tests give much more than an indication of what is likely to happen should the material being tested, be exposed to fire.
Put very simply, the test certificate says that a door or partition constructed and fitted in a particular manner passed the test. On numerous inspections I have found that fire doors have been fitted into ordinary frames, not the frame the door set was tested in. Likewise door furniture has been changed, modified or replaced with items that were not part of the original test. Drywall partitions are another example where one finds that the artisans doing the construction do not understand the need for it to be put together exactly as the manufacturer specified.
As a profession we need to become more efficient at transferring the lessons and the knowledge gained from all these incidents. Materials which gave rise to rapid spread of fire in many of the landmark fires of the 1970s and 80s are now reappearing in new guises and uses, and we see the result in some of the recent tragedies. We need to find ways to ensure the lessons are not lost, and that our successors do not have to repeat the same mistakes in order to learn from them.
The leader article in this publication in June 2017 suggested the industry needed more qualifications. Personally I feel this needs to be extended to users and installers of all fire protection systems. Better understanding of why things must be done in particular ways may help eliminate some of the more obvious faults we find time and time again. We must not forget the user in this. Several fires in what should have been robust structures have resulted in collapse, one such involved a seventeen storey building in Tehran in 2017. The reason for the structural failure was quite simply an excess floor loading in a building that had changed use, and seen an increase in fire load, with a large increase in the floor loading. The combination proved lethal for twenty firefighters.
Fire protection is a very misunderstood concept, with often competing requirements for other services ending up compromising vital components. The leader article in September 2017 suggested that we must foster a ‘whole picture’ vision, and that is, in my view, vital. Only when designers, decorators, fire protection engineers and the installers understand the implications of combining combustible window frames, with combustible surface finishes and combustible cladding, will we see a reduction of these major fire risks in many buildings.