New insights into the effectiveness of injection products against rising damp

Rising damp is a hazard to historic buildings and its relevance is expected to increase due to climate changes. The presence of rising damp in walls does not only create an unpleasant climate in buildings, but it also enhances damage processes as frost action, salt crystallization and biological growth.
The relevance of this problem is reflected by the large variety of methods against rising damp present on the market. Among these, the creation of a damp-proof course (DPC) against capillary rise by means of injection of chemical products is one of the most diffused methods. Although many of these products show a satisfactory effectiveness when assessed in laboratory tests, often a less positive result is found when assessed under practice conditions.
In the last years an extensive research on the effectiveness of injection products has been carried out in the framework of a Dutch research program. In this research, the effectiveness of several injection products has been tested in laboratory and in case studies.
The results show how not only the initial saturation degree of the wall, but even more the moisture content in the wall during the curing process of the product, plays a crucial role in whether the product will become effective. This new insight into the product behaviour constituted the starting point for the development of an innovative and quick laboratory test able to simulate the curing conditions present in practice, and provide therefore a reliable prediction of the actual effectiveness of these products.