Wall base ventilation system as a new technique to treat rising damp in existent buildings

Abstract

In existent buildings, rising damp is particularly difficult to treat, due to the thickness and heterogeneity of the walls. Traditional methods of dealing with this problem (chemical or physical barriers, electro-osmosis and so on) have proved somewhat ineffective. In recent years, numerical and experimental research into the validation of a new technique: wall base ventilation system, to reduce the level of rising damp, conducted at the Building Physics Laboratory, Faculty of Engineering, University of Porto, has yielded interesting results. This article describes and analyses the results obtained following the implementation of hygro-regulable wall base ventilation systems in laboratory and in churches in Portugal. It was defined with criterions to avoid condensation problems inside the system and crystallizations/dissolutions problems at the walls.