Chimneys convey exhaust gas produced in domestic heat appliances to the external environment and to do this they have to pass
through floors and roofs: if these elements are made up of flammable materials, the fire hazard may occur. This article presents
the verification of a 3D numerical model set for the determination of the stationary temperatures reached on the flammable
materials in the vicinity of chimneys. The verification has been done comparing the temperatures measured in experimental
tests with those estimated by means of the numerical model. Results show that the 3D numerical model is a valid tool for the
analysis of heat transfer between chimney and roof. Since in the experimental tests it is not always possible to reach stationary
temperatures, a lumped element model to estimate them is also proposed and it could support the chimney certification
