Waterproofing is one of the most critical stages in pool construction, ensuring the pool's watertightness and preventing water loss and structural damage. Since concrete is porous and doesn't provide waterproofing on its own, flexible and two-component insulation materials are used. Typically, cement-based crystalline or polyurethane-based liquid applied insulation materials are applied in at least two layers to create a perfect barrier, extending the pool's lifespan and preventing contact with groundwater.

In skimmer pool systems, water is collected from the surface through openings called skimmers, whereas in overflow pools, water overflows the edge into perimeter grates and channels, then flows into a balance tank. Overflow systems offer a more aesthetic appearance and more effective surface cleaning. Skimmer systems, on the other hand, are generally more cost-effective and involve a less complex installation.

The selection of the pump and filter should be based on the pool's total water volume and frequency of use. The pump's flow rate must be sufficient to circulate all the pool water within an ideal period (typically 4-6 hours). The filter's capacity should also be compatible with the pump's flow rate to ensure effective water purification. For energy efficiency, variable-speed pumps can be a beneficial choice.

The main options for pool interior finishes include ceramic, porcelain, glass mosaic, and liner coatings. Ceramic, porcelain, and glass mosaic offer aesthetic and long-lasting solutions for concrete pools, while liner coating is a vinyl-based membrane that serves as both insulation and finish. Liner coatings are quicker to install and generally more economical, whereas ceramic and mosaic provide greater design freedom and durability.