The thermo-mechanical behavior of masonry walls is investigated from both experimental and theoretical points of view. Fire tests have been performed in order to evaluate the thermo-mechanical resistance of masonry wall submitted to a vertical load (13 ton/m) and exposed to temperatures ranging from 20 to 1200 degrees C. As a result we measure the temperature evolution inside the wall and evaluate the vertical and lateral displacements of this wall during heating for a period of 6 h. These results are affected significantly by phase-change phenomena which appeared as a plateau around degrees C in temperature-time curves. A theoretical model was then developed to describe the experimental results taking in to account convection, conduction and radiation phenomena inside the wall. In addition, liquid water migration using an enthalpic method is considered. (C) 2006 Elsevier Ltd. All rights reserved.