Balcony Effect on the External Fire Spread into Upper Floors

This paper presents the results of an investigation on the balcony effect of the fire spread, via external windows, into upper floors. Several natural fire tests were carried out in a compartment that intended to represent a small office and the fire development inside and its spread to the upper floors was analysed. They were tested three configurations of balcony above the exterior window of the compartment; no balcony, a balcony of the same width of the window and a balcony one meter wider for each side of the window. These natural fire tests were also numerically simulated with the Fire Dynamics Simulator (FDS) software and analytically simulated with the simplified calculation methods of annex A and B of EN1991-1.2. The results of the experimental, numerical and analytical tests were compared with each other. The constructive solution for limiting fire spread into upper floors that proved to be more effective was the one with the balcony one meter wider than the window.