What waterproofing for an outdoor pool?

What waterproofing for an outdoor pool?

An outdoor pond can be adorned with rocks, fountains, waterfalls, aquatic plants, fish or ducks. But for all these elements to evolve harmoniously, your pool must be free of small holes and other damage, whether it is dug, above ground, rigid or flexible. So, find out how to avoid cracks and water leaks and which waterproofing to choose to protect your outdoor pool.

Why waterproof an outdoor pool?

Even when it is built of solid materials such as concrete, the outdoor pool must be waterproofed. Indeed, under the aggressive action of the organic matter deposited on the walls of the pool, the concrete degrades. In addition, meteorological factors and ground movements weaken the structure of the tank. Humidity, frost and drought destabilize clay, limestone and sandy soils.

This causes water infiltration and affects the aquatic ecosystem.

What type of coating to waterproof pools?

Depending on the use made of the water point, the coating material varies.

A tank that is used to store water for irrigation or fire will support an ordinary sealant. But, for ponds that contain plants and fish, toxic products must be avoided. Otherwise the biological balance of the water is affected by the lack of oxygen, in particular.

Concrete basins

Concrete pools seem the most resistant to climatic variations. But the rigidity of cement and formwork does not always resist ground movements.

Above ground pools

Since they are not contained by the soil, they are constantly under water pressure. In addition, over time, the micro-movements of the ground end up cracking them.

This is why it is recommended to seal them with a flexible casing coating. It is a mixture of cement and non-toxic chemical additives, loaded with resin. This semi-liquid coating is applied to reinforced concrete and poured concrete. It is highly corrosion resistant and waterproof.

The buried basins

A buried basin, built of concrete, undergoes the pressure of the water it contains, on the one hand. On the other hand, it is exposed to back pressure from groundwater. This is why it must be reinforced with water-repellent cement. It is a rigid dispersion resin-based sealant that guarantees long-lasting insulation. It protects the mortar against cracking and the reinforcing steel against corrosion.

The tiled pools

Concrete pools must be protected against infiltration even when their coating is tiled. The right product is a colorless resin system that waterproofs your pool without damaging its color. In fact, this high-tech liquid adheres to the coating and seals the cracks in a durable way. Simply apply it to the entire surface of the pool whether it is tiled, earthenware or mosaic.

How to use sealants?

For concrete pools, proceed as follows if you want to apply a coating such as cemaqua on cement or concrete:

• Clean the supports of any dirt;
• Sand the corners and use mortar to give them a well-rounded shape;
• Sprinkle supports with water to maintain humidity;
• Spread a first thin layer of filler using a brush;
• Leave to dry (12 hours on average);
• Apply a second coat of filler using a brush.

Buried pools require a brush to treat the angles and a trowel to apply the second coat. Note that it is not recommended to work in direct sunlight.

For tiled pools, follow these steps:

• Wash and degrease the supports;
• Moisten the supports;
• Check with a tester that the humidity level does not exceed 5%;
• Spread the primer with a soft sponge;
• Leave to dry (2 hours on average);
• Apply a first coat of filler with a soft brush;
• Leave to dry (12 hours on average);
• Apply a second coat of filler to all supports; - Apply a first layer of protective resin;
• Wait for the drying time (6 hours on average);
• Spread a second layer of protective resin.

What waterproofing for pools on tarpaulin?

Water points dug in the ground can be waterproofed using a special tarpaulin. It is a flexible coating that adapts perfectly to the contours of the dug hole.

It must be placed carefully on several people to prevent it from bending. Its maintenance must be done regularly to reduce the accumulation of detritus that degrades it. The thickness of a tarpaulin must correspond to at least 1 mm whether it is in EPDM or PVC.

EPDM tarpaulins for ponds

EPDM (Ethylene Propylene Diene Monomer) is a material that is perfectly suited to sealing outdoor pools.

This type of elastic membranes withstand water pressure and resist organic matter.

PVC pond covers

These are very flexible Polyvinyl chloride membranes which guarantee optimal sealing. The installation of elastic tarpaulins is a delicate operation because the folds are easily formed. Like EPDM tarpaulins, PVC membranes can be up to 12 m wide.

Finally, if you prefer to avoid artificial coatings, you can opt for clay. Indeed, this form of natural waterproofing is effective for pools dug on the ground. It is then necessary to apply a thick layer of pure clay over the entire surface of the basin.

All you have to do is fill your water point and admire your garden... And for more information on outdoor ponds, browse our blog for inspiring ideas!