If you have a brick home that you want to upgrade, you might consider different options for improving the facade. One possibility is to cement-render the external walls. Consider the following reasons for taking this option. Protective Effect Cement renders consist of a mixture of cement and sand, which can be combined with other elements such as lime and acrylic or polymer resins. Regardless of the specific formula, the render will add a layer of protection to the building and save it from weathering in the sun and rain.