Fire-safety authorities are studying plans to protect buildings that have combustible cladding and are evaluating if fire-resistant barriers can be added to replace the flammable exterior cladding.
The government is working with safety experts to examine methods that can be used to delay the spread of fires in older buildings with flammable aluminium cladding, an issue that has again came into the spotlight due to the recent Torch tower fire. On Friday, the blaze quickly spread to 64 floors, raising questions about how such a fast moving fire could be stalled in future.
“There are many options that are being reviewed based on science, engineering and cost. All of those things are aggressively being looked at by the government here in the UAE,” said Drew Azzara, Middle East executive director of the National Fire Protection Association.
The non-profit organisation has worked closely with federal and emirate-level civil defence authorities in training personnel, developing modules for rigorous fire inspection and on the updated 2012 Fire and Life Safety Code introduced earlier this year.
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“[In UAE skyscrapers] the fire prevention systems, the sprinkler systems, the alarms are in place and are operational. People are getting out, the fire departments, the first responders are there. But there is an existing problem and that is the exterior cladding,” said Mr Azzara.
Placing fire-resistant material at regular intervals on older buildings to partially remove the flammable cladding and adding sprinklers on balconies are options being considered, added Mr Azzara, whose organisation is working with authorities on long-term solutions.
“We are in the process of looking at some modelling to address the fire spread, like putting a banding system and replacing the cladding. If the entire surface is cladding material then the fire will run up the building,” he said. “So if you replace certain cladding with fire-resistant material every 10 or 20 metres, it will stop the migration up the building.
“Adding sprinklers on balconies because many fires start on the balcony - these are the things being looked at.”
Andy Dean, head of facades at engineering firm WSP, said fire breaks, or barriers, would help control the blaze.
“It would help stop the fire spread across the building and thereby you have a smaller fire and generally a much better scenario. This will reduce the size and extent of the fire,” he said.
In major fires that have occurred across the world, the swiftness with which the fire has spread has caught people’s attention.
“One of the dangerous and damaging aspects about these fires is that it engulfs a large part of building very, very quickly. It spreads over the facade and gets on and over the building quickly and anything that can be done to control the spread of the flames and the propagation of the fire is important,” Mr Dean said.
Experts have long said that it would be prohibitively expensive to completely replace the entire aluminium cladding on older buildings.
Combustible cladding was a worldwide issue, said Mr Azzara.
“There is a lot of research that is needed. This is a long-term process. This is not just here in the UAE, it’s throughout the Middle East, Europe and the world,” he said.
Regular tests and inspections of the fire-safety equipment were important for existing buildings with combustible cladding, Mr Azzara said.
“Inspection, testing and maintenance is important for these buildings. The first line of defence is to ensure that those buildings are maintained with the Fire and Life Safety Code operational.”
He said the priority at federal and emirate-level was training personnel on
fire building inspections.
Following the nationwide 2012 Fire and Life Safety Code, authorities banned non-fire-rated cladding consisting of a combustible, low-density polyethylene sandwiched between aluminium panels.
The studies being considered now are for buildings that predate the code.
Since 2012 there have been five major UAE skyscraper fires that spread quickly because of aluminium cladding with a combustible thermoplastic core. The blaze that engulfed the Address Downtown Dubai hotel grabbed the world’s attention on New Year’s Eve 2015.
Luckily, no lives were lost in these fires and the reason for that is because people were able to evacuate quickly and safety systems were in place, Mr Azzara said.
“They could get out of the building because the stairways, the egress was clear. If these systems are not in place that is when disasters can happen. For the most part, the systems are operating, people are getting out and we are not hearing about major disasters concerning people,” he said.
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Torch tower blaze
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Blaze rips through Dubai's Torch Tower - in pictures
Dubai torch blaze: American musician tells of night escape - video
Dubai Torch tower fire: internal e-mail shows repairs from first blaze had just been approved
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How does a fire barrier help?
Fire breaks reduce the likelihood of fire propagation, explained Andy Dean, head of facades at engineering firm WSP.
“Propagation really relates to the spread and the development of a fire. So if you have flammable material and there is ignition, then that flammable material starts to burn.
The chain reaction that causes the fire to grow and the flame to spread will hold and keep going until it comes to something that retards it.”
The blaze could be stopped by water, a change in wind direction or a fire break.
“If you retard it by introducing a fire break, you are slowing down the chain reaction and slowing the spread of flames. Think about it like a live animal eating. So instead of eating the next piece of material, it’s got to jump across the material across the panel to the other side to eat. If that bridge or jump is too big for it, then it can’t get across. It’s almost like it comes to a river.”
To illustrate this, Mr Dean used the example of the Great Fire of London of 1666. Buildings then were made of wooden timbers and packed closely together, so it was easy for the fire to spread.
Firefighters tried everything, from water to axes, to try and stop the fire but, finally, the plan that worked was one that used gunpowder to blow up houses in the path of the fire so there would be no further fuel to feed the blaze.
“A whole load of houses were pulled down so the fire would have too big a jump to make. That was like introducing fire breaks,” he said.
“So when you replace the flammable material with non-combustible material, that introduces a barrier over which the fire can’t jump and therefore retards its progress.”
