A specialty form of concrete, gunite is a mix of sand, cement, and water. To build a gunite pool, crews apply it pneumatically, which means it is shot at high velocity through a high-pressure hose. The flexible, lasting material covers a network of steel bars, forming a thick, reinforced, rock-hard pool shell.

Gunite is similar to shotcrete. It is also called a “dry mix” because—unlike shotcrete—it arrives at the job site in dry form before water is added to make the material wet.

Learn more about gunite and how it’s used with other construction materials to build pools: 5 Key Construction Terms for Concrete Designs