ROOF CHARACTERISATION RELATED TO FIRE PROPAGATION RISK BY A NUMERICAL APPROACH

The expérience shows that roofmg Systems are to be considered as a major factor of thé fire propagation in industrial buildings like warehouses. Currently in France, régulations require that two main measures be implemented to limit thé propagation of thé fïre by thé roof:- one is thé use of intumescent strips on thé roof,- thé other consists of extending thé fire walls (typically 70 cm or 1 m) above thé roof levé1 in order to prevent thé flame from being blown down onto rooftop. A set of normalised-like live tests is used to study thé behaviour of roofing Systems submitted to interior or exterior fire. Unfortunately, thé aforementioned measures are not easily modelled through live tests, and this prompted thé need to develop an accurate computer modelling method. Therefore, this paper présents a computer modelling approach aiming at studying thé influence of such intumescent strips or wall upstands on thé heat propagation properties of current roofing materials. In this paper, two kinds of roofing Systems are studied:- one containing stone wool as insulating material,- thé other containing polyurethane as insulating material. The numerical code used is Fire Dynamic Simulator12 (FDS), developed by thé NIST, with a spécial additional heat conduction module.