By Tom Symonds
Interior Correspondent, BBC News
Panels made of plastic and aluminum have been added to the sides of the Grenfell Tower to make it warmer and drier. The disguise, however, was blamed for spreading the flames when a fire broke out in June 2017 that killed 72 people.
Hundreds of thousands of people live in buildings with similar cladding that now has to be removed at an enormous cost, creating a building security crisis.
The public inquiry interviewed key employees at Arconic, the multinational metals company that manufactured and supplied the cladding panels for Grenfell.
So what did we discover?
1. This type of disguise burns easily
The big problem concerns one type of cladding called Aluminum Composite Material, or ACM. It consists of polyethylene (PE), a plastic between two very thin aluminum sheets.
France-based Arconic Architectural Products named its version of the product Reynobond PE and sold it to major construction projects around the world. There is no doubt that this product is highly flammable.
2. The cladding has consistently failed the fire tests off Grenfell for 12 years
In 2005 Arconic commissioned tests in France to determine how the Reynobond product would behave in a fire when installed using two standard methods known as “rivet” cladding systems and “cassette” systems.
Riveting systems are simply mounted directly on mounting brackets with rivets. In “cassette” systems, like old-style cassettes, the panel is folded into box shapes to hide the fixings.
It was crucial that the cassette system was the design of the Grenfell Tower.
When testing the cartridge version of Reynobond PE, the test failed to complete.
In the European standard fire test, the results are classified from A1 (best) to F (worst).
The cassette version received an E. rating. The folding appeared to allow the formation of burning plastic pools.
This version should be retested in 2011, 2014 and 2015. Every time the rating was E. Even the more powerful rivet version only managed class C in recent tests.
3. It did not meet building standards in England
The construction bible in England is called Approved Document B. It contains the fire safety standards required for all buildings.
For high buildings over 18 m, only products with the rating B in the European fire test may be used. The class E Reynobond cladding fell short of the required standard.
England has its own system of fire test ratings. The best rating is class 0 (zero), which is acceptable instead of the European standard. However, the French manufacturer of Reynobond PE never subjected this cladding to the relevant tests, the investigation said.
There were other ways to meet the regulations, including testing a design on a full model. That didn’t happen in Grenfell Tower. Arconic is now saying it should have.
4. Arconic “misled” British Standards Board
Test results are commercially sensitive. A professional body, the British Board of Agreement (BBA), evaluates them and issues product certificates.
The BBA decided that the evidence from the more successful European tests run on the Arconic siding meant it met the UK standard.
However, the board was never shown the Class E ratings for the cassette version of the fairing, and they knew nothing about it until then a BBC investigation in 2018.
The President of Arconic in France, Claude Schmidt, was forced to admit upon investigation This would have “misled” anyone reading the certificate, including British architects.
5. The Grenfell disaster was predicted a decade ago
In 2007, Gerard Sonntag, Arconic’s Marketing Manager, took part in a lecture by a consultant, Fred-Roderich Pohl, who warned dramatically about the risks of cladding aluminum composite materials. He said it had the same “fuel power” as a 19,000 liter truck of oil.
But he went even further. According to reports, Pohl asked: “What happens if only one PE building is on fire and kills 60 to 70 people?”
Exactly the circumstances of the Grenfell fire in 2017.
Mr Sonntag’s report on the presentation was exposed by the investigation which established what the company knew and when.
Image rightsReutersImage descriptionSeventy-two people died as a result of the fire
6. The company was aware of a “Towering Inferno” warning following fires in the Middle East
In May 2013 the BBC reported one worrying Series of fires in the Middle East, blamed on ACM cladding from several manufacturers.
Arconic noticed. The employees distributed an email They had been given by a sales manager who worked for a competitor, Richard Geater of 3A Composites, who described linings that had been sold as refractory “burning paper”.
It was a “scam,” Geater concluded.
When asked, Arconic’s UK sales manager, Deborah French, was asked: Why not attach a health warning to the product?
“At the time,” she said, “the risk was” not that obvious “.
7. The sale of fairings continued despite the risk
The company’s UK sales director, Deborah French, told the request British buyers were more likely to request Reynobond PE and mount the cladding as “cassettes”, the variant that resulted in poor fire tests as it allowed a “cleaner” appearance with the fixings hidden from view.
There was a tendency towards a “fire retardant” version in France, but not in the UK.
The company’s technical director, Claude Wehrle, played a key role in commissioning the fire tests. He warned colleagues and even some customers about the results. even that they should be treated “very confidentially”and the sale went on.
In the minutes of a meeting in 2011, Mr. Wehrle wrote that the disguise “exhibits bad behavior, exposed to fire”, but “we can still work with national regulations that are not as restrictive”.
8. Arconic claimed it was not responsible for the use of the panel
The company has stopped selling Reynobond PE since the fire. But it is argued that it is simply the maker of a raw material that is supplied to specialized “fabricators” who make cladding systems.
Arconic says it has no way of knowing how the products will ultimately be used, and that designers need to look into whether they can meet building codes.
However, an email sent to a customer by Sales Director Deborah French in May 2013 made a different impression.
She said the company can “control and understand” what type of cladding is used in construction projects because it only works closely with a “very small group of approved processors”.
“We can keep track of what type of project is being designed / developed,” she wrote, then offered “the correct Reynobond specification.”
When asked, Ms. French claimed that she was not telling the truth when writing the email.
9. The company knew it was selling to Grenfell
However, the investigation has evidence that Deborah French, who ran cladding sales for Grenfell Tower, knew it was a public apartment building.
In January 2013, four years before the fire, she received “artistic representations of what the Grenfell Tower might look like” after the work was completed, according to her testimony.
But she claimed for days that she “had no technical knowledge and was not involved in designing projects”.
- After taking into account the night of the fire during the first phase of the Grenfell Tower investigationIn January 2020, the focus shifted with the hearings, which focused on the redevelopment of the North Kensington building and its role in fires, as well as issues related to building regulations. This is still ongoing.