A FIRE engineer tasked with regulating Grenfell insulation firm Kingspan felt the company was "evasive with the truth", an inquiry has heard.

Phase two of the probe is examining how the block of flats in west London came to be coated in flammable materials that contributed to the spread of flames, which shot up the tower in June 2017, killing 72 people.

Module six of this phase is concerned with building regulations and the published guidance on fire safety, including detailed consideration of Government policy in this area.

On Monday, the inquiry focused on the National House Building Council's (NHBC) role in the housing industry, and in particular on safety concerns surrounding the company's Kooltherm K15 insulation – a small amount of which was used in Grenfell Tower.

Kingspan has its headquarters in Ireland, but has an insulation factory near Pembridge, Leominster.

Addressing the inquiry on Monday, NHBC surveyor John Lewis described his employer's role in the building industry as that of a "regulator".

The inquiry heard that part of Mr Lewis' role at the NHBC during its relationship with Kingspan was that of a fire engineer.

In his witness statement, Mr Lewis said that the NHBC did not have a "particularly good" relationship with Kingspan between 2013-2017.

"We felt that they were being evasive and hiding the truth," he said.

"They were a big organisation who seemed to feel that they could drive the market.

"I tried to distance myself and politely refused the offers to visit their factory.

"I wished to maintain a professional distance."

In November 2013, Mr Lewis attended a meeting with facade engineering consultants Wintech, in which the suitability of K15 for use in buildings over 18 metres in height was discussed.

Wintech told the NHBC that there had only been one BS8414 test for K15 insulation, and that was with a "very robust wall composition".

According to Kingspan's website, a BS8414 test involves "a fire breaking out of a window and exposing a cladding system to a severe fire".

Mr Lewis said he came to the view the BS8414 test wall had been "over-engineered" in comparison with walls that would actually be used in many real-world building projects.

Mr Lewis told the inquiry that when he raised these issues with Kingspan, he found their knowledge was "very limited".

"When we quizzed Kingspan as to what evidence they had for the combustibility in the use of that product we found that there was just the single 8414 test", he said.

"And then apart from that the BBA (British Board of Agrement) certificate and the LABC (Local Authority Building Control approval."

Mr Lewis told the inquiry that he raised the issues with the combustibility test in a meeting with Kingspan representatives in January 2014."

"I recall from the meeting that when we put all this to them, they didn't disagree with any of it or really deny any of it," he said.

The inquiry continues.