Cement for swimming pools: choosing the right type

A swimming pool is first and foremost a reinforced-concrete structure: base slab, walls and copings rest on a designed, cast structure built with a cement of the right class. So "which cement for my pool?" has a two-part answer: a structural cement for the basin itself — and dedicated products, distinct from cement, for waterproofing and finishes. Confusing those two levels is the most common — and most expensive — mistake in pool projects.

The structure: demanding reinforced concrete

Base slab and walls are designed like any buried structure: water load, earth pressure, possible high water table. For a standard in-ground pool, CPJ 45 (45 MPa at 28 days) suits the structural concrete. CPJ 55 earns its place for large basins, heavily stressed structures or salt-exposed sites — coastal locations in particular, consistent with Dakhla's climate. That choice belongs to the design: have it validated by the professional sizing the pool.

Waterproofing does not depend on cement

Concrete, even well dosed and well cured, is not watertight by nature: it is porous and micro-cracked. A basin's watertightness rests on systems built for it — reinforced membranes, liners or elastic waterproofing renders — installed to their manufacturer's specifications, on a mature, clean substrate. No "waterproof cement" replaces those systems on a pool: a hydrophobic admixture in the concrete can reduce the substrate's capillarity, it does not do the waterproofing alone. That distinction matters: promising otherwise is planning leaks.

Care for what will decide everything: the casting

Structure quality conditions the waterproofing laid on top. Three requirements dominate. Compact casting: careful vibration of walls and slab to eliminate gravel nests — future water paths. Serious curing: moisture kept for several days after casting to limit shrinkage and micro-cracking. Treated construction joints: joints sanded, cleaned and bonded with grout before casting resumes. On a pool, every shortcut of this kind is paid back in leaks that are hard to locate.

The finish: products rated for immersion

For pool tiling, EN 12004 calls for a class C2 adhesive, often a C2TE S1 or S2 (deformable) variant; waterproofing itself falls to a dedicated system beneath the tiling. Joints must suit treated water (chlorine, salt) and thermal cycles. Here again, these are specialised products, distinct from structural cement — and we do not manufacture them.

A soil question before anything else

Before choosing any cement, the soil survey dictates the design: ground nature, water presence, bearing capacity. A slab on expansive clay or a pool in a high water-table zone calls for specific measures (drainage, raised slab, pumping during works). Those decisions belong to the pool designer; our role is limited to supplying a class-compliant binder, tested on every batch, and pointing you to the good casting practices described above.