In the major part of this lecture, I will present a model for drying  shrinkage of mesoporous materials which considers capillary and  surface adsorption effects. As such it can be applied over a wide  range of humidity, a concern for nuclear waste packages which has to  be disposed in environment of low humidity for at least 50 years in  France. The model is derived from thermodynamics and needs as input  only the sorption isotherm from which a BJH analysis provides with all  information. The model is validated on many different materials during  adsorption and desorption. In particular experimental strains measured  during the desorption of cement paste and vicor glass exhibit  non-monotonous variations which are captured with the model, without  any additional fitting parameters. Physical insights gained with the  model permit to understand the dominant forces at stake during the process of drying. In the last part of this lecture, I will present  briefly a model suited for microporous materials such as coal. This  model was applied to explain the transient permeability of fractured  coal seams as observed in the field.