London — One of the makers of exterior composite boards on the Grenfell Tower housing complex that was destroyed in a 2017 fire that killed 79 people is telling officials in a public inquiry that building designers did not understand United Kingdom fire safety ratings.
Celotex, a building products business of Saint-Gobain that made many of the PIR boards used to insulate the Grenfell Tower, said in opening statements for the inquiry that six different types of insulation were used to refurbish the tower.
Products included PIR made by Celotex and Kingspan Group. U.K.-based Kingspan also made phenolic board used on Grenfell. Some extruded polystyrene also found its way into the gaps around windows.
No Kingspan insulation products were specified in the refurbishment.
The June 2017 fire turned deadly when a fire that began in a home appliance spread to the outside of the building, where it quickly moved up the side of the building, trapping residents in upper floors in their homes.
Fire investigators have blamed the construction and products used on the exterior.
Celotex said during the inquiry that it had only limited interaction with designers and specifiers in the refurbishment process. It sold products through third-party builders merchants.
The company's position is that people working on the project did not spot the problems with design and materials choices. However, emails between people at these companies showed that they knew how flammable the outer covering was.
When it came to the insulation, key people seem to have assumed that "Class 0" surface spread of fire is the same as limited flammability, Celotex said. It stressed that the two things are different.
