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

This week, the inquiry heard the most senior witnesses from Kingspan,

the company which made some of the insulation installed on the outside of Grenfell Tower.

And we learned the Kingspan technical team joked about the company's

K-15 insulation, not achieving the fire classifications it was advertised with. All we do is lie in

here, one Kingspan employee wrote. Also, just six weeks after the fire, Kingspan hired a PR company

to help them lobby MPs who are deciding

future building regulations. Kingspan then designed a test with another company's non-combustible

insulation, so it would, as they put it, have the best chance of performing poorly. This meant

they could argue to a parliamentary select committee that non-combustible products could be just as dangerous as their own K-15.

Now, Kingspan's witnesses have been appearing at the inquiry for the past two weeks, and I don't want to spend too much time going over the same issues.

So before we start this week's evidence, let's quickly go over what we've already

learnt. My colleague May Cameron is with me. So quickly, Kingspan made plastic foam insulation,

which was combustible. It couldn't pass tests to show it was of limited combustibility,

the standard recommended for high-rise buildings by building regulation

guidance in England and Wales. So to be used in this situation, Kingspan needed to pass

a large-scale fire test, setting light a mock-up of an entire cladding system, complete with

insulation, cladding panels, cavity barriers, and so on. That approved the system as a whole, not individual

products, for use on high-rise buildings. In 2005, Kingspan passed one of these tests,

with its insulation, cool-firm K-15, alongside non-combustible cement fibre boards. But a year later,

it changed the way its material was produced.

And when Kingspan tested the new version of its product in another large-scale fire test,

...