Treating rising damp in the walls of historical buildings is complex because moisture transfer into the walls of old buildings in direct contact with the ground leads to the migration of soluble salts. This work analyzes rising damp using concepts and methods of unsaturated moisture flow theory, and a numerical validation study. A simple analytical model describes the rising damp front for the simplified situation of a monolithic wall. The influence of wall thickness, boundary conditions, wall composition, and material properties, such as porosity and sorptivity, are analyzed in detail.