Can you tell us which resins can be used for paints suitable for masonry surfaces ?
If the main requirement is to achieve a water repellent effect without sacrifing water vapour permeability, then we would recomend the use of coating compounds based on silicone resins.
Such finishes will generally also protect the surface against blooming due to the presence of salt residues within the masonry.
Solvent based as well as water based silicone products are on the market for application to brick walls. An alternative solution is to use paints based on vinyl acetate and acrylic copolymers. Acrylate dispersions have lately been used for this purpose with great success, especially with vinyl and vinylidene chloride modified grades.