Evaluation of Moisture Transfer to Improve the Conservation of Tiles Finishing Facades

The research of methodologies and tools to improve the durability of building components has the aim to find out the strategies to increase the service life, minimizing the environmental impacts. The paper refers on clinker facades, especially after the repairs of mortars due to severe damages. The authors achieved on-site investigations on a prominent study case in Leonardo Campus, at Politecnico di Milano, and laboratory tests to study the interaction between moisture and cement mortars, the decay effects, and the protective treatments to improve the mortar durability. The research sharpens the methods for the evaluation of water absorption and moisture transfer in external building components and proposes possible strategies of intervention. The methodology focuses on the characterization of the water behavior in mortars by different tests, the experiments in laboratory on mortars samples, to study the hygroscopic and capillarity absorption properties, and on site, through visual analysis and nondestructive techniques. The researchers studied a water-repellent protective treatment to apply on the finishing surface and evaluated it in terms of water-repellent efficacy, compatibility with the substrate, vapor permeability, and color stability. The investigations provide input data, useful for simulating the moisture transfer, validating the experimentations, and modeling the physical mechanisms, which occur on the façade. In addition, the method analyses also the optical characteristics of the surface, with the aim to detect any change due to the application of further protective treatments and for aging process.