New technique for treating rising damp in historical buildings: Wall base ventilation

Abstract

Abstract Intervene in historic constructions increasingly requires extensive and objective knowledge of what one will be working with. The multifaceted aspect of the works needed on this kind of constructions tends to encompass a growing number of different tasks, with the imperative need to know the causes of many of the problems that affect these buildings and the possible treatments that can solve them. Moisture transfer in walls of old buildings, which are in direct contact with the ground, leads to a migration of soluble salts responsible for many building pathologies. We know that many of the techniques currently used to reduce rising damp are not much effective, when dealing with walls of considerable thickness and heterogeneous materials, as is the normal case of historic constructions. Bearing this in mind, a new technique to treat rising damp in historic constructions has been developed and patented in Portugal. The technique consists of ventilating the base of walls through a natural ventilation process or by installing a hygroregulated mechanical ventilation device. The process of development and validation of this new technique will be presented as well as the most recent studies to improve it. A detailed presentation of the diagnosis, design and works made on a historic building in the north of Portugal, will be done. Some system limitations and some corrections that needed to be performed will also be presented.