1 PARRACHA J.L., LIMA J., FREIRE M.T., FERREIRA M., FARIA P. Vernacular Earthen Buildings from Leiria, Portugal: Material characterization. International Journal of Architectural Heritage.Int. J. Architectural Heritage, https://doi.org/10.1080/15583058.2019.1668986 Vernacular Earthen Buildings from Leiria, Portugal - Material Characterization João Luís Parracha a,b , José Lima c , Maria Teresa Freire d,e , Micael Ferreira a , Paulina Faria a,e* a Department of Civil Engineering, Faculty of Science and Technology, NOVA University of Lisbon, Caparica, Portugal; b Department of Structures, National Laboratory for Civil Engineering, Lisbon, Portugal; c Faculty of Architecture, University of Lisbon, Lisbon, Portugal; d Department of Materials, National Laboratory for Civil Engineering, Lisbon, Portugal; e CERIS, Civil Engineering Research and Innovation for Sustainability, Instituto Superior Técnico, Lisbon, Portugal. * Corresponding author: Paulina Faria, CERIS and Department of Civil Engineering, Faculty of Science and Technology, NOVA University of Lisbon, 2829-516, Caparica, Portugal; E-mail: paulina.faria@fct.unl.pt ABSTRACT In Portugal a large number of vernacular earthen buildings present an advanced state of degradation. These buildings comprise historical, technological, architectonic, cultural and social recognized values and, therefore, efficient interventions are needed for their conservation. The knowledge of the properties that the materials used in their construction show nowadays is one of the bases to support future interventions. Unstabilized earthen samples were collected from the walls of six earthen buildings located in the region of Leiria, Portugal, built with rammed earth and/or adobe masonry. The samples were characterized by particle size distribution and through XRD, density, capillary, drying, dry abrasion, tensile and compressive flexural strength. Mechanical results of rammed earth were lower than adobe’s, contrary to what was commonly found in other studies, and capillary coefficients of adobe were comparable to lime stabilized adobe from other regions. A surface protection by compatible renders,