A report on the tragedy, which killed 71 people, found that the material was so conducive to the spread of flames that it had defeated the usual fire service advice to “stay put” within barely half an hour, the inquiry on Grenfell was told.
The findings were contained in a report by fire safety expert Dr Barbara Lane.
She said tests had shown that the cladding materials did not comply “with the recommended fire performance” set out in guidance for a 25-storey building and that there were “multiple catastrophic fire-spread routes created” within the tower.
Dr Lane said a “culture of non-compliance” could be seen at Grenfell from the number of fire safety measures which were deemed inadequate.
She wrote: “I have found no evidence yet that any member of the design team or the construction ascertained the fire performance of the rain screen cladding system materials, nor understood how the assembly performed in fire.
“I have found no evidence that Building Control were either informed or understood how the assembly would perform in a fire.”
The report was one of four released as the first day of evidence got under way before Sir Martin Moore-Bick in Holborn Bars, London.
A second report, departing from information given at earlier briefings by Scotland Yard, said there was “insufficient evidence” that the fire was started by a fridge-freezer.
Prof Luke Bisby wrote: “I have not seen sufficiently convincing evidence to confidently identify the origin of the initial fire.”
The origins of the fire were also said to be “undetermined” in a report by forensic scientist Professor Niamh Nic Daeid.
In his opening remarks, Richard Millett QC, counsel to the inquiry, said: “The fundamental question which lies at the heart of our work is how, in London in 2017, a domestic fire developed so quickly and so catastrophically that an entire high rise block was engulfed, and how it was that 71 people lost their lives in a matter of hours, leaving family and friends in shock, grief and bewilderment.”
The commissioner of the London Fire Brigade, Dany Cotton, who was at the scene from 2.29am, has told the inquiry in a statement: “I have never seen a building where the whole of it was on fire. Nobody has ever seen that. It was incredible. It was alien to anything I had ever seen.”
Mr Millett said the Grenfell investigation was the “largest public inquiry ever established”.
There are 533 individual participants, of whom 21 are children who have not been named. Some 29 organisations are also participating, including 19 commercial bodies, eight public bodies and two trade unions.