By Jawad Hmayed
Picture taken from Shafaq news
It is another Tuesday morning in the city of Beirut, people woke up, got dressed, and were heading to reach their jobs downtown. Everyone got shocked at the sight of a black smoke rising from the north Beirut Souks; is it another fire? What is it today? It has been only 6 weeks since a fire caused a terrible and huge explosion that is noted to be one of the largest in history. What was shocking is that the fire is also a few hundred meters away from the port. Hence, flashbacks of the horrible Beirut explosion and the huge fire hit the Lebanese people. The word has been spread, and it turned out to be a fire of the beautiful piece of art by Zaha Hadid, the Aishti building under construction in the north Beirut Souks on the 17 of September 2020. Fortunately, no one was injured, and the fire turned out to be an accident in the use of a blowtorch.
The fire that went up in the Zaha Hadid building in the Beirut North Souks is another tragedy that needs to be dissected and understood in these difficult times in Lebanon. Health and safety protocols are not being followed up and given attention in Lebanon for a quit long time; and especially lately the whole country has been facing economic difficulties that took everyone’s attention. To understand the cause of the fire at this building; first, we must look at the material used, the design of the building especially where the fire originated, and how such design helped its expansion.
Zaha Hadid was exceptionally known for her usage of beautiful and high-tech material in her structures and magnificent artworks. She uses Glass- Fibre Reinforced Concrete as in the Heydar Aliyev Centre, Glass Fibre Textile as in Serpentine Sackler, and a combination of aluminium and stone cladding as in Galaxy Soho. These materials are highly flammable. That is why some countries such as Australia started banning the use of them. In fact, in New South Wales, aluminium composite panels (ACPs) with a core comprised of more than 30% polyethylene (PE) by mass has been banned for use in any external cladding, external wall, external insulation, façade or rendered finish in buildings. As of August 15, 2018, the ban came into effect and has not been revoked.
A combination of aluminium and stone cladding was frequently used by the construction teams in Ms. Hadid’s designed buildings to cover the external wall of the building and was used in Beirut’s structure. These are generally two thin sheets of aluminium separated by a core material. The core can be made up of PE, mineral fiber or a combination of both, and can contribute to how easily the cladding burns and its potential to spread fire. Polyethylene is a highly combustible polymer, and when it is in high density, this material becomes highly flammable because of its thermoplastic composition, thus allowing the fire to expand on its surface melting the aluminium sheets and spreading the fire.
The design of the building included several layers of coating, namely from the interior to exterior: Gypsum board – limp mass barrier (sound proofing)– void – rock wool – polyurethane (PU) a waterproofing material – glass and glass reinforced concrete(GRC), and fiberglass resin. The sketch and west façade figure below show how these materials where designed and executed. From the above materials listed, PU and the limp mass barrier (limp vinyl with a layer of reinforced aluminium foil facing on one side) are the materials that immediately catch fire. The other materials are also flammable but require elevated temperatures to ignite. The voids in the façade design creates a shaft for flames to ascend through and that is the reason behind the upward expansion of the fire.
Looking at what caused the fire, we should be aware of the section design where the fire originated. At the ground level, where the retaining wall ends, a coating of styrene-butadiene-styrene (SBS) is usually used to seal and coat the concrete retaining wall to make it water proof; this is done by heating the SBS with a blowtorch to seal and merge the different materials together. At the upward end of the retaining wall, there is a transition from the retaining wall to the façade of the building and this is where the SBS is in connection to the PU. Hence sealing the SBS above the finished floor level with a blowtorch most probably ignited the PU and caused the fire to reach the rest of the material.
Fortunately, no one was injured in the Aishti fire however it spread fear and panic among a severely traumatised population. A prevention method for the expansion of such fires could be developed by introducing a complete fire zoning system not only from floor to floor as designed but also it should be implemented in the façade. This usually done by eliminating shafts/voids that expanded the flames by using fire-rated foam. Taking such measurements and including them in the design of any building is going to increase the costs. There is nothing more important than the human right of living in a safe environment hence implementing such measures should not be debatable. In addition to that in case of fires the financial damages would be extremely high. As a result, reducing cost on the expense of safety protocols, such as using fire-rated material and an efficient fire zoning, could be highly damaging in case of accidents.
On 14 June 2017, a similar accident took place where a fire broke out in the Grenfell Tower, in North Kensington, West London. The fire caused 72 deaths, more than 70 were injured, and 223 people managed to escape. In this accident the fire similarly grew through the building’s exterior cladding and the air gap which caused a similar Stack effect. In conclusion, special safety protocols should be forced and implemented to guide the usage of aluminium-cladding since next time we may not be so fortunate.
References:
– Waterproofing material Submittals, technical data sheets of the Zaha Hadid building
– https://sciencing.com/how-12071421-make-polyethylene-fire-retardant.html
Secondary Authors:
- Alaa Al Mikkawi
- Abdel Aziz Kordieh
- Amira Fawaz
- Abir Hajj Houssein
- Carl Zoghzoghi
- Christelle Rassi
- Malak El Kassamani
- Marc Darazi
- Mohammad Asaad
- Mohammad Daoud
- Nadeen Abbas