> The Grenfell Tower disaster was horrific, and although the subsequent building regulations that limit height were clearly reactionary in nature Grenfell was

> The Grenfell Tower disaster was horrific, and although the subsequent building regulations that limit height were clearly reactionary in nature Grenfell was a failure of regulations to be applied and bad retrofitting. The cladding was supposed to conform to a specific rating that means it doesn't cause fire spread. Ie, it can burn, but as soon as a heat source is taken away it stopped burning (its more complex than that, but you get the idea that its not supposed to just burn like crazy) What actually happened is that the fire rating that was given to it was suspect, and it wasn't applied correctly. I had assumed that the type of insolation (either EPS or Polyisocyanurate) was fire proof, as in I doesn't burn like a plastic bag when exposed to flame. Because thats what the fire rating implies. However there are two standards and its a bit hazy. You can have something like rockwool, that doesn't burn as well as industrial packing polystyrene(EPS) which does. In the 70s when these buildings were built, they had the right idea[1]: concrete boxes with a brick skin. Minimal holes between the flats, and any hole was liberally blocked with asbestos. THe problem came when asbestos was removed, or the external walls were covered in a flammable non-encased/fire compartmentalised cladding.