Testing new water repellent solutions to protect deteriorated granite

The evaluation of nano-particle based products to protect granite surfaces from water income is presented in this paper. Wettability, water absorption, drying behaviour and water vapour transfer were considered as the most relevant parameters for this evaluation. The effect of the application methods on the final performance was also tested. The results allow to consider that nanostructured products may present some advantages when compared with conventional water repellent products, namely on some common relevant harmful effects, such as colour changes, water vapour or liquid transfer during drying, but their effectiveness as barriers against water absorption in longer contact time may not be equally satisfactory. KEY-WORDS: Granite, water repellent, superhydrophobicity