Fecha de publicación: -- Fuente: Materials The increasing emphasis on sustainability in the construction sector has revived interest in the use of raw earth materials as eco-efficient alternatives to industrial construction products. Earthen plasters, applied as protective and decorative coatings on earthen and masonry walls, exhibit advantageous hygrothermal and environmental properties. However, the drying phase of earthen plasters is often accompanied by shrinkage and cracking, which compromise mechanical integrity and aesthetic quality. This paper presents a comprehensive experimental and numerical investigation of the drying behavior of raw earth plasters composed of sand and montmorillonite clay. Laboratory experiments were conducted to characterize the physico-mechanical and hydric behavior of various sand–clay mixtures after implementation on a porous support, followed by numerical modeling using COMSOL Multiphysics. The experimental program included consistency tests, drying kinetics, shrinkage and suction measurements, and mercury intrusion porosimeter (both on support and plaster). Numerical simulations employed the Richards equation coupled with the van Genuchten - Mualem model to capture unsaturated flow and deformation during drying. Experimental results show that an optimum sand–clay ratio is critical to minimizing cracking while maintaining sufficient adhesion on support and plasticity for implementation. The combined approach provides insight into the mechanisms of shrinkage and cracking and serves as a predictive framework for designing durable, low-carbon earthen plasters suitable for sustainable architecture.