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Hello and welcome to the Grenfell Tower Inquiry podcast with me, Kate Lamble.

This week, a fire engineer from the UK's largest private building control body,

said advice described in the inquiry as dangerous should not have been written.

He made a frank admission when questioned about the organisation's

relationship with the building industry. Did it ever occur to you that this act of collaboration

was, in one sense, corrupting? Well, I think we probably knew that, but I can't give any

reasons more. That was the thinking of the industry at the time.

And two days after the Grenfell Tower fire, a senior civil servant contacted an expert

asking her to publicly support the government's assertion that the type of cladding used on Grenfell

was not permitted in the UK. Let's get started with the evidence then. Both of the witnesses we're going to hear from

this week came from the National House Building Council who provide warranties on the vast

majority of new build homes in the UK. The NHBC, as they're known, also offer one of the largest

independent building control services in the country. While the NHBC didn't play any part in the refurbishment of

Grenfell Tower, their dominance in this market is why the inquiry is so interested in how they

approved combustible building materials for use. And the product the inquiry focused on for much of

this week was an insulation called K-15, produced by the industry leader, Kingspan.

K-15 was widely used. At one point, an email shows one NHBC staff member claimed,

Without exaggeration, every, underline down in bold, every building SRPM deal with, which are over 18

meters in height, on extremes now pushing

250 metres in height, proposed stroke have used Kingspan K-15.

K-15 is the same material which was installed on around 5% of Grenfell Tower.

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