Gunite - review

Gunite is applied by blowing a mixture through a hose. A sand-cement mix is blended with water at the nozzle. This creates sprayed concrete which can be used to make free-form shapes.

Gunite can be sprayed against a shape formed by:

• excavation into soil
• wire mesh supported on a metal or framework
• stiff fabric supported on a wooden framework
• inflated air bags

Large structures benefit from reinforcement but the use of expansion joints in gunite is unusual. This is because gunite concrete is thinner than cast concrete and the steel mesh on which it is sprayed is strong.

The surface of gunite is rough after spraying. It is therefore covered with a cement render (plaster) or ceramic tiles.