Coarse plaster is a type of wall covering that is made up of a combination of cement, sand, and water. It is often used in exterior walls and is known for its durability and weather-resistant properties. The two most common types of coarse plaster are roughcast and STUCCO. Roughcast is a type of coarse plaster that is applied to the surface of a wall using a trowel and then left to dry. STUCCO is a type of coarse plaster that is applied to the surface of a wall using a sprayer and then left to dry. Both types of coarse plaster provide a durable and weather-resistant finish to exterior walls.