The assessment of effectiveness and compatibility of water repellents in heritage masonry conservation: laboratory tests and non-destructive investigation through IR thermography

Moisture jeopardizes the durability of historic buildings by speeding up the deterioration mechanisms. One way to protect the historic masonry walls from exterior moisture agents is the application of water repellant chemicals. Those chemicals have been used as surface treatments for more than 60 years in historic buildings for conservation purposes. However, most of the time the effectiveness and the performance of the treatments are not evaluated after the onsite application. In this thesis, the evaluation of the effectiveness of those chemicals is investigated through IR thermography and other lab techniques. Small-scale brick samples are used to obtain qualitative and quantitative data to assess the behavior of the brick when it interacts with moisture through capillary action. Moreover, those data are used to compare the results with the thermal image that are obtained from a masonry wall made with the same commercial bricks. These comparisons are aimed to propose a cheap, effective, and continuous monitoring method for the evaluation of the effectiveness of surface treatments for the preservation of historic buildings.