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Rainscreen cladding relies upon convection through the cavity between the insulant and the fascia to prevent water ingress, however cavity fire barriers should be installed at specified locations to prevent the very same convection transmitting fire through the cavity many times faster due to the effect of the high temperatures as hot air rises very much faster than the design convection rate. In cases where the convection rate is too high, any cavity barriers that are present and not properly and fully fixed will be dislodged and swept away instantaneously, leaving a ‘firestorm’ within the cavity, propagating the fire faster than most people could imagine. Any materials which may be inert and fire resisting at normal temperatures in the rainscreen and insulation system will reach explosive flashpoint and contribute towards the firestorm effect. But the cladding is only part of the situation. A complete lack of adequate escape width for the number of residents is equally to blame as are ‘stay put’ fire strategies. Designing modern buildings requires you to ‘take one escape stair out’ and calculate the escape width on the remaining staircase(s). A ‘medium’ risk building with 600 occupants should have a minimum 3075mm escape width in ‘protected shaft staircases’ with smoke lobbies, and more than one staircase. Surely it’s time to abandon passive fire safety, ‘stay put policies’ and start to retro install additional escape stair towers on the exterior of all tower blocks. It may cost and may lose some flats, but it’s not rocket science, and should be an immediate priority.