A two-dimensional model of heat and mass transport within an oriented strandboard (OSB) mat during the hot pressing process is presented. The thickness of the mat changes with time during pressing, and a novel approach to calculating gas flux accounts for the resulting compression of the OSB mat. The gas within the voids is treated as a binary mixture of air and water. Model parameters are obtained from the literature and from direct measurements. The simulation results are compared to measurements taken within panels of two different target thicknesses from an existing industrial manufacturing operation.