Exterior wall treatment is a job that involves applying a material such as STUCCO to the outside of a building. STUCCO is a type of plaster made from cement, sand, and lime that is applied in multiple layers to create a protective coating. It is often used to protect walls from weathering and to give them a decorative finish. STUCCO is a popular choice for exterior wall treatments because it is durable, low-maintenance, and relatively inexpensive.