A concrete pool that starts to gray, with a rough bottom underfoot or a surface that shows small blisters: the coating shows its limits. Before considering a major renovation, pool paint offers a more accessible solution to restore a clean appearance and provide long-lasting protection for the concrete substrate against water, chlorine, and temperature variations.
Why raw concrete is not enough as a pool coating
Concrete is porous. Left unprotected, it absorbs treatment water, which accelerates its degradation. Micro-cracks widen season after season, and limescale deposits become embedded in the roughness.
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Applying a pool paint for concrete creates a waterproof barrier between the substrate and the pool water. This layer limits infiltration, makes cleaning easier, and provides a uniform color that enhances the visibility of the bottom.
Without this protection, renovation becomes more expensive: it may be necessary to redo the coating, treat deep cracks, and sometimes install a PVC or polyester liner. Painting on time avoids a major renovation of the pool.
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Epoxy, polyurethane, or chlorinated rubber paint: which product to choose
Three families of paints dominate the market for concrete pools. Each serves a specific purpose, and the choice depends as much on the condition of the substrate as on the frequency of pool use.
Epoxy paint for pools
This is the most common product for concrete pools. Epoxy paint forms a hard film, resistant to treatment chemicals. It adheres well to a properly prepared substrate (smooth, dry, slightly sanded coating).
Its main advantage: epoxy paint offers the best mechanical resistance among common options. It withstands friction, repeated traffic, and pH variations. In return, it requires a longer drying time between coats and does not forgive poor substrate preparation.
Polyurethane paint
More flexible than epoxy, polyurethane paint better absorbs the micro-movements of concrete. It is suitable for pools that already have slight surface cracks. Its flexibility also makes it more comfortable under bare feet.
Polyurethane is a good compromise between flexibility and durability. Its UV resistance remains acceptable, although it deteriorates slightly faster than epoxy under prolonged exposure.
Chlorinated rubber paint
Less technical to apply, this paint dries quickly and is easy to renew. It is suitable for pools that require frequent refreshing. Its lifespan is shorter, but its cost and ease of application compensate for seasonal use pools.
Preparing the concrete substrate before applying paint
Have you ever noticed that some pool paints peel off during the first season? In the vast majority of cases, the problem comes from substrate preparation, not the product itself.
A poorly prepared substrate condemns the paint to peel off. Here are the steps to follow before any application:
- Completely empty the pool and let the concrete dry for several days. Residual moisture prevents paint adhesion, especially for epoxy products.
- Clean the substrate with a high-pressure cleaner to remove limescale deposits, algae, and remnants of the old coating. Any greasy residue compromises adhesion.
- Repair cracks and chips with a repair compound suitable for damp environments. Smooth as much as possible to avoid thick spots that create weak areas.
- Lightly sand the surface to open the pores of the concrete. This mechanical scratching allows the paint to anchor into the substrate.
- Apply a primer if the paint manufacturer recommends it. Some epoxy paints can be applied directly, while others require this intermediate layer.
Skipping any step reduces the durability of the coating. A carefully prepared pool will last significantly longer than a pool repainted in a hurry.
Applying the paint: conditions and mistakes to avoid
The success of the painting depends greatly on the conditions at the time of application. Painting in direct sunlight or humid weather compromises the result, even with a high-quality product.
Apply the paint in dry weather, between 15 and 25 °C, away from direct sunlight. These conditions allow for even drying, without bubbling or too rapid surface drying (which traps moisture under the film).
Why a minimum of two coats? A single coat leaves areas of low thickness, especially in corners and vertical parts of the pool. The second coat evens out the protection and fills in the micro-defects of the first.
- Use a short-pile roller for flat surfaces and a brush for corners, interior copings, and sealing areas.
- Respect the drying time between coats indicated by the manufacturer. Applying the second coat too early traps solvents that weaken the film.
- Do not fill the pool before the paint has fully cured. This time varies depending on the type of product: it is longer for epoxy than for chlorinated rubber.
Maintaining the painted coating to extend its lifespan
Once the pool is refilled, regular maintenance plays a direct role in the longevity of the paint. A stable pH protects the paint film as much as the concrete.
Water treatment that is too acidic or too basic attacks the painted surface and accelerates powdering (this whitish powder that detaches when rubbed). Keeping the pH within the range recommended by the treatment product manufacturer limits this degradation.
For cleaning, prefer a soft brush rather than a robot with abrasive brushes. Aggressive cleaning accessories scratch the coating and create entry points for water under the paint film.
A localized touch-up is possible if an area is peeling. Simply sand the damaged part, degrease, and repaint with the same product. Quickly repairing a chip prevents water from infiltrating under the healthy layer.
The lifespan of a painted coating varies depending on the chosen product, the quality of the initial preparation, and water maintenance. A well-maintained pool retains its appearance for several seasons before requiring a complete new application, making it a more accessible renovation option compared to installing a PVC liner or a polyester shell.