What is pool gunite?

Summary: A mixture of cement and sand sprayed onto contoured and supported surfaces to build a pool. Gunite is mixed and pumped to the site dry, and water is added at the point of application. Plaster is usually applied over the gunite. The plaster is actually the material that is visible and that comes into contact with the water (not the underlying gunite cement structure).

More details: "Gunite" is a trade name for "dry gunned" concrete, invented and patented by a North Carolina man. The term "gunite" has been used so much that, to most people, it means spray applied concrete. People often talk about a gunite pool -- meaning a concrete pool where the concrete is pneumatically applied or sprayed in place using air pressure. Many of us in the concrete spraying business have started using the term "dry gun" to delineate this process.

"Dry gun" means the cement and sand are injected into an air stream conveying it to the nozzle. The nozzle operator then adds the water at the nozzle and has total control of the water-cement ratio. The delivery hose of the mix is generally quite light, as the hose is mostly filled with air containing the mix of cement and sand.