The guniting technique is a construction system consisting of projecting concrete with a "cannon" (in English "gun") or high-pressure hose, being able to build on any type of surface, including earth, with the aim of achieving a continuous wall, with greater resistance and less thickness, to support and contain the pressure exerted by the ground, with any type of slope, offering optimal waterproofing thanks to low porosity.

In some countries this technique is also known as projecting, which can also consist of spraying mortar "Mortar (construction)") (without the coarse aggregate). In English it is called build-up: layered gunning (or layered spraying), application of shotcrete in successive layers to form a thicker mass (build-up is also the residual accumulation of hardened concrete inside a mixer or concrete mixer).

One of the advantages of this technique is the greater resistance per square meter, that is, with less material, greater resistance and durability are achieved. It also results in the firmness of the structure that is gunite by obtaining a compact and solid layer.

This technique can be used to line ravines and prevent risks of possible landslides, with a degree of durability that makes maintenance minimal.

Gunite has revolutionized the world of pool construction, since it adds to total waterproofing, optimal tightness of the pool shell as there are fewer pores in its walls. Thanks to the versatility of this technique, pools with original designs can be built even if they have complicated shapes for traditional techniques, with optimal finishes.

The development of this technique has given rise to a new way of applying continuous coatings to buildings, leading to the appearance of a new range of mortars with specific characteristics to facilitate spraying, normally known as single-layer mortars, although not all single-layer mortars are sprayable nor are all sprayable mortars designed so that the coating is completed with a single layer. Specific mortars for single-layer spraying usually contain synthetic components in their dosage.

The application of gunite is done with mortar pumps, concrete pumps or dry gunite machines.