Specification checklist for exposed-aggregate pool finishes: an architect’s guide

Last updated: 28 October 2026

A practical specification checklist for architects and pool builders covering sample approval, area calculation, substrate acceptance, edge detailing, and start-up care for exposed-aggregate pool finishes.

Specifying a cement-based exposed-aggregate pool finish requires defining the finish, interfaces, responsibilities, and acceptance requirements rather than simply naming a colour on a drawing. Because the finish is a decorative layer—not structural repair or waterproofing—the specification must coordinate sample approval, area measurement, substrate acceptance, transition detailing, and initial water care to align the design team, main contractor, and specialist applicator.

1. material line, colour, and sample approval

Start by matching the surface texture and underwater response to the architectural setting. Within the PebbleCrete range manufactured in Phuket, Thailand, all three lines are cement-based finishes applied at a nominal 10 mm thickness.

• Record which line is specified — PebbleCrete Classic, PebbleCrete Supreme and PebbleCrete Glass — and the exact colour name, and reference the materials guide for the aggregate of each line. Approve the choice on a current physical sample viewed wet and an on-site mock-up.

Include three sample verification items in the specification:

• Line, colour, and current sample reference: Request a current physical sample from PebbleCrete, confirm availability or custom blend requirements, and record the sample reference in the contract documents.
• Sample viewed wet: Screen images and dry samples cannot show how water depth, sky reflection, and shade alter apparent colour. Review the physical sample submerged in water under sun and shade alongside proposed coping and terrace finishes.
• On-site mock-up approval: Because natural stone and glass vary slightly between batches and application is by hand, require an on-site mock-up (test panel) for sign-off before main installation. Judge the completed surface against the approved physical sample and mock-up rather than digital illustrations.

2. measured finish area and application scope

Separating material supply, preparatory works, and specialist installation prevents scope gaps between trade packages.

• Measured finish area: Calculate the actual surface area to be covered — floors, walls, steps and sloped beach entries below the operating water level. Submerged benches, overflow channels, coping and any surface outside the waterline need a separate project specification and should be listed separately. Plan water-surface area excludes vertical and stepped surfaces and cannot be used as the finish quantity.
• Planning coverage figure: Allow approximately 1.8 m² per 25 kg bag at a nominal 10 mm thickness as a planning figure; actual usage depends on pool geometry, curves, and substrate regularity. The aggregate is supplied in 25 kg bags (40 bags per pallet where palletised) and requires project-specific quantity and delivery planning, including advance batch planning on large hotel or resort pools to manage batch-to-batch colour consistency across large areas.
• Supply and application responsibilities: PebbleCrete supplies packaged finish materials and technical documentation; independent professional applicators carry out installation unless agreed otherwise in writing. Name the party responsible for supplying specified locally sourced white Portland cement, preparing the base, producing the mock-up, and carrying out the hand application.

3. substrate, render, and waterproofing acceptance

In the pool system build-up, wall alignment, floor falls, step geometry, and level corrections belong to the prepared watertight base and render—not to the finishing coat.

• Decorative role defined: State explicitly that the exposed-aggregate finish is decorative: it is not structural repair or waterproofing, and must not be used to conceal unresolved leaks or construction defects.
• Substrate and render acceptance: Require inspection for moving cracks, exposed reinforcement, or weak and hollow render, with agreed repairs completed beforehand. On both new builds and renovations of tiled or plastered pools, require documented substrate assessment and acceptance, referring preparation and bonding procedures to approved project documentation. Bond coat: A bond coat connects the finish to its prepared base; on a renovation of a tiled or plastered pool it is not optional. Name who specifies, supplies and applies it and confirm its compatibility with the prepared surface and the finish.
• Waterproofing and water-test sign-off: Identify the waterproofing system, confirm compatibility across the build-up, and record a signed water test and photographed substrate inspection before finishing begins.

4. movement joints, transitions, and fittings

Resolve junction details and hardware clearances on drawings before the applicator arrives on site.

• Waterline tile, polished bands, and overflow edges: Surfaces alternating between wet and dry collect mineral deposits at the air-water interface. Specify a coordinated waterline tile band under the coping or a smooth polished aggregate band (terrazzo treatment), keeping the operating water level inside the maintainable zone. On beach entries and lagoon shallows, design gradients and drainage so the finish preferably stays wet; areas that repeatedly wet and dry need a project-specific edge detail.
• Steps and contrasting markers: Define tread depths, riser heights, edge radii, and contrasting tile or aggregate step markers so treads read clearly underwater. Specify a matching colour where PVC spacers are used.
• Movement joints: Carry structural and movement joints cleanly through the continuous finish using project-designed movement joints, compatible interfaces, and approved drawings.
• Fittings, levels, and lighting: Require clearances and completed levels for main drains, bar gratings, skimmers, inlets, and underwater lights to be checked against the intended finish build-up and fitting details. For fibre-optic or projection lighting, coordinate cable routes and light-source access beforehand and record concealed paths on handover drawings.

5. water treatment and start-up responsibilities

Across Southeast Asia and the Middle East, high ambient temperatures and variable source water make handover planning essential. Well, river, or lake water can arrive at pH 5.5; adding trichlor without correcting pH and alkalinity can visibly etch a cement-based finish within six months.

• Site readiness and filling water: Complete nearby dusty or overhead work and clean balance tanks, sumps, and pipework beforehand. Require an agreed filling and start-up plan under current approved start-up instructions, a suitable water supply, and a named responsible operator.
• First-month start-up and operating targets: Name the operator responsible for continuous filtration, daily brushing during the first month, and logging water tests. Confirm targets against the pool’s treatment system, approved care guidance, and applicable local requirements, particularly for commercial pools:
• pH: 7.6–7.8 (working range 7.2–7.8; below pH 7.6 the water slowly begins to draw on the cement matrix, so the target sits at the upper end. Assess pH alongside alkalinity, calcium hardness, and the saturation index under the approved care guidance)
• Balance parameters: Total alkalinity 80–120 ppm; calcium hardness 200–400 ppm; Langelier Saturation Index 0.0 to +0.3 (acceptable −0.3 to +0.3)
• Sanitiser and salt: Free chlorine 1–3 ppm for every system (salt chlorinator, liquid chlorine or trichlor) (cyanuric acid 30–50 ppm). Dose via the balance tank or skimmer—never directly onto the finish—and wait 28–30 days after fill before adding salt (staying within the chlorinator manufacturer’s range, typically 3000–4500 ppm).

6. documents to request and service life planning

State your company name, the project name and country, and the product line to request current project documentation from PebbleCrete before work begins:

• Technical Data Sheets (TDS) and Safety Data Sheets (SDS): Confirm product details, current revision, and site handling requirements.
• Method Statement and Substrate Acceptance Protocol: Verify that the applicator follows the current approved application and start-up procedure and records formal sign-off of the prepared base.
• Material warranty and submittals: Request the Submittal package, recommended installer warranty template, the Manufacturer’s Declaration of Origin where the project requires it, and the manufacturer’s material warranty, which is separate from installation workmanship cover.

As a planning figure, an exposed-aggregate pool finish is generally expected to serve for 15–20 years. This is an industry estimate, not a warranty term. Where an individual pool falls within or outside that range depends on substrate preparation, application quality, water chemistry and routine maintenance.

Frequently asked questions

Photographs and screen colours are illustrations. Confirm colour and texture with a current physical sample viewed wet and an approved on-site mock-up.

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This article provides general technical guidance, not a design, installation or safety instruction for a specific pool. Every project depends on its structure, substrate, waterproofing, water conditions and local regulations. Refer to the current PebbleCrete technical documents: the Technical Data Sheet and the Installation Overview are available online, and the Safety Data Sheet and the full Method Statement are issued on request. Confirm structural, waterproofing, electrical and installation decisions with qualified professionals. PebbleCrete supplies the material only; unless agreed otherwise in writing, substrate preparation and application are carried out by the owner’s applicator, who is responsible for that work. Nothing in this article limits your statutory rights.