Yup, that's what the building regs say, that's what the manufacturers say, all we really don't know is why they were used anyway. It appears at this point that the manufacturer's sales dept sold the boards to the cladding installer knowing full well what they were going to do with them (makes them culpable for their greed imo) but not if the installer understood they weren't adequate for what they were doing with them.At the end of the day if the cladding burns it shouldn't be used on a tower block, at least not one as high as Grenfell.