The mechanical properties of adobe earth block depend largely on their state of drying thus a study of this phenomenon was made. A method for determining drying time of wet earth sheets is described, where the process is controlled by diffusion of water through the material and evaporation from the surface. Short tests were used for determining the kinetics governing the weight loss of the sheet allowing water diffusivity and evaporation rate to be obtained. A model based on an explicit numerical method with finite differences was applied to this problem and enabled the estimation of drying time of earth blocks. This could be applied to adobe blocks. Graphs, 9 references.