Before the pool construction begins
The construction phase proper begins only after several upstream decisions have been made. The pool’s position on the site, its dimensions, its overflow configuration, and the hydraulic layout must all be resolved before excavation starts. Changes made during construction are costly – changes made on paper are not.
A soil survey is strongly recommended before breaking ground. It characterises the ground conditions – bearing capacity, presence of rock, and water table level – and determines the foundation type and structural reinforcement required. On sloped or constrained sites, it is not optional.
The technical drawings – pool geometry, sectional profiles, hydraulic piping layout, overflow edge detail, and plant room design – serve as the shared reference for every trade on site. Without them, each contractor works to their own interpretation of the project. With them, the construction follows a single technical intent from excavation to commissioning.
Excavation works
Before excavation begins, the pool’s exact position and dimensions are marked out on the ground from the drawings. This is the moment to verify that the pool’s location matches the design intent – once the ground is broken, changes are costly. The position of the balance tank and the plant room are equally important and must be confirmed at this stage: once construction has begun, none of these elements can be relocated.
The pool structure
The pool floor is poured as a reinforced concrete slab. Before the concrete is placed, all floor-mounted fittings – bottom drain, floor return inlets, and cleaning nozzles, if specified – must be positioned and sealed precisely. This is one of the most critical stages of the build: once the slab has set, these positions are permanent and cannot be corrected without breaking the structure.
Wall construction follows the slab. The walls incorporate the suction and return inlet positions, underwater light housings, and any wall-mounted equipment. Pipe runs through the walls connect each fitting to the plant room.
The upper ring beam is the most technically demanding pour of the entire project. For an infinity pool or a zero-edge pool, it incorporates the overflow profile and the gutter channel. The level and geometry established here determine the quality of the water sheet for the life of the pool. A variation of a few millimetres at this stage creates an uneven overflow that cannot be corrected without structural intervention.
The hydraulic circuit and plant room
The hydraulic circuit connects every fitting in the pool shell to the plant room through a network of rigid PVC pipes. The circuit must be pressure-tested before backfilling – any leak identified at this stage can be corrected; a leak discovered after the pool is finished cannot be.
The plant room houses the pump, filter, water treatment equipment, and any additional equipment – heating, automation, and in-floor cleaning valve. Its layout follows the hydraulic sequence: from balance tank suction through filtration and treatment to return. The balance tank regulation circuit – level sensors, float valves, and the automatic top-up connection – is an integral part of the system, not an addition to it. A plant room designed in this logical order is faster to install, easier to maintain, and simpler to diagnose when a fault occurs.
The waterproofing and finishing
Pool waterproofing is applied to the complete shell before any surface finish is laid. The method depends on the chosen lining: a reinforced PVC membrane, glass-fibre reinforced polyester, or marble-based waterproof pool render are self-waterproofing and require no additional treatment layer.
Tiles, glass mosaic and natural stone require a dedicated waterproofing treatment applied to all surfaces, joints, and penetrations before laying.
The chosen interior finish determines the visual character of the pool and the colour of the water. For overflow pools, the finish extends into the gutter channel and the visible faces of the overflow edge. These surfaces are in constant contact with moving water and must be specified accordingly.
Coping stones frame the pool edge and are set with a slight outward slope to direct runoff away from the pool. On the overflow sides, no coping is laid – the overflow profile forms the edge directly.
Where the chosen finish requires a waterproofing treatment – tiles, glass mosaic or natural stone – a first filling of the pool before laying the finish is strongly recommended. This allows the waterproofing layer to be tested under real hydrostatic pressure before the surface finish conceals any defect. The cost of this additional filling is negligible compared to the cost of identifying a leak after tiling is complete.
Commissioning
The first filling is not simply a matter of adding water. It is the moment when the hydraulic system is verified under real operating conditions for the first time. The pump is primed, the filtration circuit is balanced, and the overflow behaviour is observed across the full length of the overflow edge.
For an infinity pool, commissioning confirms that the overflow profile is level, that the water sheet is continuous and even, and that the balance tank regulation system maintains the correct water level automatically. Any adjustment to valve settings, flow rates, or level sensor positions is made at this stage – before the pool is handed over.
Pool construction methods
An infinity pool and an overflow pool can be built using several structural methods. Each produces a reinforced concrete shell – the differences lie in how the concrete is formed and placed.
Cast concrete
The traditional method for in-ground pools: metal or timber shuttering panels are assembled around a steel reinforcement cage, and concrete is poured in a single continuous operation. It produces a dense, homogeneous shell with precise dimensional control. It requires skilled formwork teams and appropriate equipment and is well suited to rectangular or geometric pool forms.
Shotcrete
Concrete is projected at high velocity onto a steel reinforcement framework, building up the shell layer by layer. Shotcrete is particularly well suited to free-form pools and complex geometries – the process follows the shape of the reinforcement rather than the shape of a mould. It is widely used for large residential and commercial pools. The quality of the result depends heavily on the skill of the operator.
Concrete formwork blocks
Factory-moulded concrete blocks are assembled dry around vertical steel reinforcement, then filled with fluid concrete poured from above. The blocks act as permanent formwork – they remain in place as part of the finished wall.
This method produces a fully reinforced concrete structure with the same structural performance as poured concrete or shotcrete, but with a construction process that is accessible to a wider range of contractors, including general builders with no specialist pool experience.
Morana's advice
Each stage of an infinity pool build depends on the one before it. Pipe positions set in the slab cannot be moved once the concrete has cured. The overflow profile cast into the ring beam determines the water line for the life of the pool. Commissioning can only confirm what the construction has produced; it cannot correct structural decisions made earlier.
This is why the quality of an infinity pool is determined long before the water is added. It is determined by the precision of the technical drawings, the competence of the trades, and the rigour of the supervision at each critical stage.
Frequently Asked Questions — Infinity Pool Construction
What is the most critical stage of infinity pool construction?
The three most critical stages are: pipe installation before the pool slab is poured – positions cast into the concrete cannot be moved without breaking the structure; the casting of the peripheral tie, which incorporates the overflow profile and gutter channel and permanently sets the water level and overflow geometry; and commissioning, where the hydraulic circuit is balanced and the overflow behaviour is verified for the first time. Errors at any of these stages are difficult or impossible to correct without major structural intervention.
How long does it take to build an infinity pool?
For a standard residential infinity pool built by an experienced team, construction typically takes three to four months from excavation to commissioning. This does not include the design and planning phase, which should begin well in advance. On complex sites or international projects with coordination challenges, the programme may extend to six months or more.
Can any contractor build an infinity pool?
An overflow pool requires specific technical knowledge – particularly for the overflow edge geometry, the hydraulic circuit, and the balance tank integration. A general contractor or mason with no prior experience of overflow pool construction can build one successfully, provided the technical drawings are sufficiently detailed and supervision is in place at the critical stages. The construction method – cast concrete, shotcrete, or concrete formwork blocks – does not determine the quality of the result. The precision of the execution does.