Gunite is a dry mixture of sand and cement that is hydrated at the nozzle and sprayed at high velocity onto a steel reinforcement cage. Because it is applied rather than poured into forms, it takes any shape the steel takes, which is what makes concrete pools fully custom. You will also hear the term shotcrete, which refers to a wet-mix version of the same idea.
1. Design and layout
Everything starts with the property, not the pool. Grades, drainage, access, sightlines from inside the house and the position of the sun through the afternoon all shape where the pool should sit. Once the design is settled, the shape is laid out on the ground so you can walk it before anything is dug.
2. Excavation
The hole is dug to the pool's profile with allowance for the shell thickness. This is the stage where site conditions assert themselves: rock, a high water table or a steep grade all change method and duration. Spoil is removed or, where the design allows, used for grading elsewhere on the property.
3. Steel and rough plumbing
A reinforcing cage is tied to engineered spacing throughout the shell, and plumbing runs for returns, skimmers, main drains and any water features are set. Anything that will be buried behind concrete is placed and pressure tested now, because it cannot be revisited later without cutting.
4. Gunite application
The shell is sprayed in a continuous operation, then hand-carved to final profile including steps, benches and ledges. Curing follows over the next several days and is not optional: concrete gains strength through hydration, so the shell is kept wet on a schedule. Rushing this stage compromises the structure permanently.
5. Tile, coping and decking
Waterline tile and coping are installed, and the surrounding deck is built. This is the stage where the pool starts to read as part of the house, and where material choices matter most visually. Decking is also where drainage has to be right, so water moves away from the pool and the house rather than pooling on the surface.
6. Interior finish
The interior finish is applied over the cured shell. Options range from standard plaster through aggregate and polished finishes, and the choice affects both the water's apparent colour and the surface texture underfoot.
7. Fill, start-up and handover
The pool is filled without interruption, since a pause during filling can leave a permanent line on a fresh finish. Equipment is commissioned, water chemistry is balanced through a start-up period, and the system is handed over with instruction on how it runs.
How long the whole thing takes
Most full projects run a single season. Curing and finishing stages have minimum durations that cannot be compressed, and in Ontario and Atlantic Canada the weather window sets the outer boundary. A schedule that promises otherwise is worth questioning.
Common questions
What is the difference between gunite and shotcrete?
Both spray concrete onto a steel cage. Gunite is a dry mix hydrated at the nozzle, while shotcrete arrives pre-mixed. Both produce a structural shell that can be formed into any shape.
How long does gunite take to cure?
The shell is kept wet on a schedule over roughly a week before finishing continues, and concrete keeps gaining strength well beyond that. Curing is not a stage that can be rushed without permanently weakening the structure.
Can a gunite pool be any shape?
Effectively yes. Because the shell is formed on site over shaped steel, geometry, depth, ledges, benches and integrated features are limited by design and engineering rather than by a manufactured mould.
