The former product manager at the firm which manufactured the flammable insulation boards used on Grenfell Tower’s flawed refurbishment has called the actions of his former employer “completely unethical”, the inquiry has heard.

Jonathan Roper, who worked at Celotex between May 2012 and April 2016, told Monday’s hearing how the insulation manufacturer deliberately exploited “ignorance” within the construction industry about fire testing regimes to sell its combustible RS5000 product for use on high-rise buildings.

It came after Roper admitted last week how Celotex had rebranded its combustible FR5000 insulation, which had failed the fire test needed for use on buildings above 18m in February 2014, as a “new” product called RS5000.

…