Conservation of heritage building materials is an important issue and no doubt climatic condition seriously affects the monumental building materials. The surface protection of heritage building materials by water repellent treatment is an essential requirement to control the weathering action of water and other related factors. Recently, with the technological development, many new products have been introduced in the market with high claims of their performance as a preservative coats. The protection of cultural heritage buildings and monuments by surface coatings with polymers is a common practice due to their ability to form a protective invisible transparent layer on the surface of monuments and control the transport of different fluids from the surface to the monument’s interior. Protective coatings are used to make the building material more resistant to deteriorating agents like water, micro vegetation growth, and pollutants. To improve hydrophobicity, now a day’s many commercially available masonry water repellents are in practice.