Fire Safety Science Digital Archive

The paper describes a heat transfer model for prediction of the thermal response of woodframed exterior walls constructed with 105 mm by 105 mm wood post, gypsum board attached to the wood post on the interior side of the wall, insulation foam between posts, an air cavity of ventilation purposes, and a 12 mm thick non-combustible (ceramic) exterior siding attached to the wall over the wood strapping. This is a typical Japanese ‘post and beam’ type exterior walls. This paper examines the fire resistance of this type of wall when the exterior face of the wall is exposed to fire. The model calculates heat transfer through the siding, the air cavity, wood strapping, foamed-plastic insulation, wood posts and the gypsum board on the interior face. Mass transfer was not considered in this model. When the calculated results were compared to the results from full-scale fire-endurance tests, very good agreement was observed. The paper also describes the effect of the thickness and density of the exterior siding and gypsum board on the fire resistance of the exterior walls.