DUBAI // A “successful” fire test in 2007 on the exterior wall panels to be used on The Address Hotel in Downtown Dubai was meaningless because it did not test flammability, according to the engineer who supervised it.
The National has obtained the original US fire test for the aluminium composite panels used on the building and interviewed the man who oversaw it.
He says that test measured fire containment and not flammability.
While the distinction may not be immediately clear, fire engineers say there is a critical difference. And an analysis of the original test conducted on the panel system reveals why it is important.
“It is a flame spread issue – not a fire resistance issue,” said the engineer who has since left the Texas laboratory where the test took place. He has requested that his name be withheld.
“This product should have been tested and should have passed the NFPA 285 test to be considered as an exterior facade material on a high rise building.”
The NFPA 285 test measures fire propagation. It was not part of obligatory building codes when the tower was built but it is part of existing codes.
Why such a test was not done, even in the absence of a specific code requirement at the time, is just one of several questions raised by an investigation into the panels used on the building based on interviews with architects, fire engineers, manufacturers and contractors spanning the UAE, Europe and the US.
International experts interviewed by the newspaper agree that a flammability test should have been done rather than one that just measured fire containment.
The reason for this is that aluminium melts at about 660°C degrees centigrade. A testing furnace reaches more than 1,000°C. So an aluminium cladding panel would start to melt within minutes of a test procedure commencing.
• Read the first part of Sean Cronin's investigation here
The results of that process carried out on the hotel’s exterior wall system reveal for the first time how the manufacturer of that system could claim it survived a furnace for one hour and 42 minutes.
On the evening of December 31, 2015, thousands of revellers had gathered in Downtown Dubai to ring in the New Year. The vast development built by Emaar Properties, the owner of The Address Hotel, has become the home of new year’s festivities ever since the world’s tallest tower was opened there in 2010.
But soon the crowds were watching in shock as the 63-storey building was engulfed in a fire that took just minutes to leap 40 storeys up its exterior walls.
The flames were visible across the city as millions of people around the world watched it live on TV.
So how did the wall panel system that was to be used on that building survive a furnace for ten times longer than it took for The Address to burn?
One explanation can be found on the first page of an 18-page report of that test that has been obtained by The National.
It reveals that the aluminium panels being tested were first attached to gypsum wallboards before being exposed to a furnace.
There is no suggestion that the test process was in any way improper, or the methodology unusual. However fire engineers say that the results tell us nothing about the flammability of the panels and that a different test should have been done instead.
Speaking exclusively to The National, the man who oversaw it agrees.
While The Address cladding was being tested in Texas, some 13,000 kilometres away in Dubai, tower cranes covered the city’s skyline. From the Marina to Business Bay, hundreds of skyscrapers were under construction.
It was a time of unprecedented building activity.
Most of those buildings were covered with aluminum composite panels, favoured by architects for their clean finish and insulation properties – and by developers for their speed of construction.
It was big business for the companies that made and installed the panels.
One of those companies was Alumco, which five months earlier had been awarded a US$23.5 million supply contract on the building which was then called The Burj Lake Tower.
The main contractor on the project was an Arabtec-Besix joint venture, while the designer was Atkins – the company that also designed Dubai’s iconic Burj Al Arab.
Alumco was this week conducting its own test on the panels it used on the building.
“My crew and I spent the majority of the day launching our own private investigation on what could have caused the spread of fire vertically,” said Alumco chief executive, Samer Barakat in a January 03 email.
“We have reviewed all our documents and to top that we also did physical tests on the same materials … and it was found to be non-combustible under the extreme heat we applied it.”
But the trail of the hotel’s wall panels does not end with Alumco.
It in turn contracted Sharjah-headquartered Eurocon Building Materials, the maker of the world’s largest brand of aluminum composite panels marketed as Alubond USA.
Eurocon is a unit of Mulk Holdings and the Alubond panels that it manufactures are exported to 90 countries worldwide.
The composite panel system that was to be used on The Address Downtown Dubai underwent a test known as ASTME 119 which measures how well a building system prevents a fire from spreading to an adjacent space.
It is set by the American Society for Testing and Materials and it was conducted on January 10, 2007, at the Southwest Research Institute in San Antonio, Texas.
The engineer who supervised the procedure that day said it tells us nothing about the flammability of the system used on the hotel.
But more alarmingly, it would have produced similar results regardless of whether an aluminum composite panel was being tested or not, say experts.
A brief account of what happened that day explains why.
According to the report, subsequently used by Alubond as part of its marketing materials, the test sample comprised a wall of metal studs and fire-rated gypsum board with the composite panels fixed to the side facing the furnace.
The test was stopped after one hour and 42 minutes after the aluminum composite panels had been completely consumed. The gypsum wallboard was intact.
One of the failure criteria for the test is the appearance of flames on the unexposed side of the wall. What happens on the exposed side, where the aluminum composite panel is fixed, is not recorded.
That is because the test does not care about what happens on the exposed side.
It is the unexposed side that counts, which in real life might be an emergency exit in a building or a room containing hazardous materials.
A resistance to fire test requires a construction apparatus that is resistant to fire – which is why the aluminum composite panels being tested on that day eight years ago were fixed to a gypsum wall.
Fire engineers say it was that gypsum wall that would have represented the main resistance to the spread of fire through the system being tested.
The supervising engineer agrees.
“It was the gypsum board,” he said in a telephone interview from Texas. “The material has absolutely nothing to do with fire resistance. You can test it with the material on or off and get the same results. The use of that test data, even if the material in the building was exactly what was tested, provides no useful data for what happened in that fire.”
Art Parker, a fire engineer with US-based Jensen Hughes consultancy, said the qualification test regularly used in the US is NFPA 285 and that the ASTM E119 may also be required to provide “some degree of fire resistance to limit the spread of fire both horizontally and vertically”.
The report also reveals that the panel that was tested that day did not come from the Alubond factory in Ajman, but from an affiliated Alubond operation in Rockford, Illinois.
In many countries there are strict “chain of custody” rules that govern the testing of such products to ensure the item being tested is of the exact same type as the one that is eventually used on the building.
It is understood that no such checks were in place in the UAE when this tower was being built.
It is not known whether such a process was used during the procurement of the panels used on The Address.
There is no suggestion that the panel system that was tested then was different to the one eventually installed in the building.
The material used in the core of the panel that was tested on January 10, 2007 was not disclosed at the time, according to the supervising engineer.
He said there was no requirement for a client to provide such information at that time.
However, in order to fully comply with the ASTME 119 standard a so called “hose test” is conducted after the panel has been subjected to the furnace – which measures how a panel retains its structure when a fire hose is applied to it.
The requirement was conceived with the approach of American firefighters in mind – which is to enter a building and extinguish a fire at its source where possible – whereas in some other locations the priority is to prevent the fire from spreading to adjacent buildings.
It has emerged that this hose stream test was not conducted at the request of the client – Eurocon Building Industries and Alubond.
So the wall system was described as being “in general accordance” with the standard rather than in full compliance with it.
It is not known why that test was not requested. However the report reveals that at the end of the procedure the aluminum panels had been “totally consumed”.
Fire engineers point out that there would have been nothing left to hose after the test other than the gypsum board test assembly upon which the panels were mounted.
There is no suggestion that the Alubond panels did not comply with relevant UAE building codes of the time.
It is not known if the panels used in the building are still manufactured by the company.
However Alubond does cite the ASTME 119 rating on at least one of its products called Alubond U.S.A Fire Rated.
It says on its website: “The entire cladding system has been certified successfully under ASTME 119 level certification. Alubond U.S.A cladding systems has the HIGHEST system fire resistant rating (T rating) of 102 minutes in the one hour systems fire testing for ASTM standards classification.
A key question arising from the New Year’s Eve blaze is what kind of material was contained in the core of the panels that became engulfed in flames so quickly. Some clues are provided by analysing other recent fires in the city.
A 2013 report from the Fire Protection Research Foundation analyses several high rise fires around the world that involved aluminum cladding systems and cites three from the UAE in 2012 alone: the Al Tayer Tower blaze in Sharjah, the Saif Belhasa Tower fire in Tecom and the Tamweel Tower fire in Jumeirah Lake Towers.
It was published before the Torch Tower blaze in February 2015.
According to that report, in all three fires, the panels were found to have a polyethylene core – which is typically highly flammable.
An executive at Eurocon Building Material Industries told The National that the panels used on the exterior of The Address Hotel in Downtown Dubai also contained an unspecified amount of low density polyethylene, better known by the abbreviation LDPE.
This confirms the guesses of fire engineers interviewed by The National over the course of the past eight days who say the speed and violence of the blaze was consistent with the use of polyethylene.
The same 2013 study also highlights the “very rapid” spread of fires up buildings that have what it describes as U-shaped channels, referring to structures with inset balconies.
“It is expected that this external profile enhances re-radiation to combustible surfaces and creates a chimney effect, increasing vertical ventilation of the fire,” the report said. It recommends further research into the fire patterns on such buildings.
The Address Downtown Dubai tower also has this facade profile but it is not yet known if this contributed to the blaze.
The investigation by The National into the testing of the aluminum composite panels used on the building highlights serious issues around the fire safety of tall buildings constructed in the emirate before the introduction of new codes in 2012.
It shows that panels containing highly flammable plastic-based cores were used frequently by contractors and that the fire tests conducted on some of them may have provided a false sense of security for developers. Such tests provided no indication on how those panels propagate fire.
It also shows that there were no procedures in place to ensure that the panel systems that did undergo fire tests were of the same type as the ones used in buildings. Such procedures are now in place.
But as a report from the Fire Protection Research Foundation indicates, the use of highly flammable polyethylene panels has also been documented in a number of countries worldwide.
Because such exterior cladding fires represent a small proportion of overall building fires (between 1 and 3 per cent) and because they tend not to produce as many fatalities, emanating from outside rather than inside a structure, the threat they pose has received little attention.
But a spate of such cladding-related fires in recent years in the UAE and elsewhere is increasingly focusing the spotlight on them and their causes.
Emaar Properties, the developer of The Address, and designer Atkins declined to answer specific questions relating to the fire tests conducted on the exterior cladding panels of the building or whether those panels contained flammable polyethylene material.
Emaar also declined to confirm if any of its other buildings contained exterior cladding of a similar design.
An Emaar spokesperson said: “The incident is under investigation and we are awaiting the final report.”
A spokesperson for Atkins referred all enquiries to Emaar.
A spokeswoman for the Southwest Research Institute declined to comment on specific tests for confidentiality reasons.
Mulk Holdings did not respond to emailed questions.
A Dubai Civil Defence investigation into the fire continues.
scronin@thenational.ae
