Modelling study, funded by Kingspan, concludes tenability inside Grenfell flats was independent of insulating material. Kingspan is the manufacturer of one of the insulation cladding products which burnt in the Grenfell Tower fire. The three-part modelling study now published (parts 4 – 6), totalling over 70 pages, follows on from parts 1 – 3 (see pinfa Newsletter n°121) which suggested that mineral wool spreads fire faster than polymer insulation. Parts 4 – 6 of the study model the fire spread across the building cladding, and model tenability (heat and toxic gases) in the flats and in the common spaces (lobbies and stairs) in the tower during fire. Models compare polyisocyanurate (PIR) insulation (as used on Grenfell) to mineral wool insulation, in both cases behind ACM-PE (aluminium composite material – polyethylene) cladding as used on Grenfell. The modelling assumes, based on data from Grenfell, that the window frames deform in fire heat, then the window glass shatters, allowing fire from the external cladding to enter flats. The modelling shows that once this has occurred, conditions inside the flat are driven by burning of furniture, not by the cladding fire. Non-tenable conditions are generally reached firstly because of heat, rather than gas toxicity. The main contribution to gas toxicity comes from furniture burning in the flats. Conditions in the lobbies and stairs were very variable and strongly influenced by opening of doors to burning flats.
E. Guillaume et al., Fire and Materials Fire and Materials, “Reconstruction of Grenfell Tower fire”, parts 4, 5 and 6:
– Part 4: Contribution to the understanding of fire propagation and behaviour during horizontal fire spread, 2020, 44, 1072–1098., https://doi.org/10.1002/fam.2911
– Part 5: Contribution to the understanding of the tenability conditions inside the apartments following the façade fire, 2022;1-28 https://doi.org/10.1002/fam.3054
– Part 6: Numerical simulation of the Grenfell tower disaster: Contribution to the understanding of the tenability conditions inside the common areas of the tower, 2022,1-19 https://doi.org/10.1002/fam.3053