The article discusses the problem of heating the wall in connection with the occurrence of a fire source. The conditions of convective heat exchange with the environment are considered on the wall surface. At a known ignition temperature of wood, the time it takes for the wall surface to reach this temperature is found. The problem is solved for a homogeneous wall made of a single material, as well as for an inhomogeneous wall in which a thin layer of wood is followed by a thick thermal insulation layer. The problem is solved analytically, as well as by the finite element method. The solution of the problem by the finite difference method is also considered.

Keywords: wood, thermal insulation layer, ignition temperature, convection, finite element method, finite difference method, thermal conductivity problem