Water leaks in concrete pools: Repair them with Molins

The swimming pool season is already underway and it is now when the possible damages suffered during the winter, such as small cracks, leaks and filtrations, begin to be detected. In the latter case, there are different factors that can cause this problem in concrete pools. We explain how to detect them and repair them correctly with Molins products.

Water leaks in swimming pools can become a real headache for pool owners. In the current context of rising energy prices and drought, in addition to being a problem, they can also cause significant water losses and significantly increase maintenance costs.

However, there are effective solutions to repair these leaks and preserve the functionality of our pools. In this new Molins blog post, we analyse different methods for detecting them and the best products for repairing them.

Concrete pool leaks: Are they frequent?

Leaks in concrete pools are not the most common, although they can occur due to structural defects in their construction and also due to other factors aggravated by extreme weather conditions, ground movements, etc.

Precisely one of the greatest advantages of concrete pools is their durability and strength. When built correctly, they can be very solid and last for many years. However, it should be remembered that concrete is a porous material and over time it can also develop cracks.

Among the main causes of leaks detected in concrete pools we can find:

Cracks in the concrete lining:

They can be caused by ground movement, settlement, temperature changes or construction problems.

Problems at the joints:

Expansion joints and construction joints are areas prone to developing leaks if not installed correctly or if damaged.

Problems with accessories:

Filter pump connections, pipe connections, drains and skimmers may leak if seals or connections are not tightened properly or if they are damaged.

It is therefore important to maintain the pool properly and to carry out regular inspections to confirm possible water leaks. Thus, if a leak is suspected, it is necessary to have a professional pool repair specialist assess the problem and advise on the necessary repairs.

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How to detect leaks in concrete pools? We explain the steps for a correct repair.

Detecting leaks in concrete pools can require a thorough investigation and monitoring process. And we review some of the most commonly used techniques:

Visual observation:

Although it may seem obvious, a detailed inspection of the pool for visible signs of leaks is essential. The first thing to look for is possible areas of dampness, cracks in the concrete liner, subsidence or changes in the water level, etc.

Cube test:

Place a bucket filled with water on the pool steps or on a submerged platform and mark the water level inside the bucket. Then wait 24-48 hours and check if there is a significant difference in the water levels inside and outside the bucket.

Dye test:

Turn off the filtration systems and allow the pool water to settle. Then add a food dye or leak test dye to the water near suspect areas, such as cracks or fixtures. Watch for the dye to disperse or fade to certain areas, which could indicate the presence of a leak.

Pressure test:

Close all pool fittings and make sure the water level is at its normal level. Then turn off the filtration system and close the valves. Use a pressure gauge to measure the pressure in the system and observe if there is a gradual decrease in pressure over an extended period of time. This could be an indication of a leak in the system.

Inspection with specialised equipment:

In some cases, specialised equipment such as infrared cameras or acoustic detection equipment may be necessary to help locate hidden leaks in the concrete lining.

Without a doubt, it is essential to contact specialised technical professionals because they have the experience and equipment to detect and repair leaks in a precise and appropriate manner for each installation.

Learn more with Molins: How to waterproof a swimming pool already built?

Repairing water leaks in concrete pools

Repairing water leaks in concrete pools is essential to maintain the integrity and functionality of the pool in perfect condition. Leaks can cause structural damage, waste of water and energy and increased maintenance costs. Fortunately, there are effective methods to address this problem to ensure optimum condition.

As mentioned above, the first step in leak repair is to identify the exact location of the leak. Different detection methods can be used, such as visual inspection, bucket test, dye and pressure test. And once the leak has been located, the best measures for a proper repair are discussed, depending on the type of leak.

In the case of cracks in the concrete liner, a specific pool sealant can be used to fill and seal the cracks. This sealant is designed to be resistant to water and chemicals used in swimming pools.

It is applied directly onto the crack and smoothed to ensure a uniform surface. Molins has a siloxane modified polymer filler ideal for water immersion sealing: BETOFLEX MS45.

If the leak is in an expansion joint or construction joint, the affected joint may need to be replaced or repaired. This may involve removing the damaged joint and replacing it with a new one, or repairing it by applying special sealants. BETOFLEX MS45 mastic can also be used for these cases, if necessary using a joint filler as recommended in the technical data sheet so that the depth is proportional to the width of the joint, this system aid is ROUNDEX supplied by Molins.

In some cases, where the leak is more complex or related to problems in the pool fittings, it may be necessary to dismantle the fittings and carry out more detailed repairs. This may involve replacing seals, tightening connections or replacing faulty fittings.

Ultimately, repairing water leaks in concrete pools is a crucial process in maintaining the integrity of the facility. Identifying the exact location where the pool is leaking and using the appropriate repair methods, such as sealants or joint replacement, are essential steps in solving the problem.

And, in any case, we recommend that – although cracks are normally detected in summer when the pool is in use – it is much better to carry out this type of repair in winter, when the pool is completely empty. High temperatures can also affect some of the materials used to seal cracks.

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Molins products for repairing water leaks in concrete pools:

We have the best waterproofing products in Molins: from quick sealing to get out of cracks, concrete joints with pipes, skimmers, expansion joints, we can go with BETOFLEX MS45, hardens and adheres even in the presence of moisture and under water, suitable for permanent immersion, without contaminants, free of isocyanate.

For deeper repairs, where we need to pour the flexible hydraulic mortar PROPAM® IMPE FLEX, it is the most suitable, placing it in the crack and embedding the elastic band BETOTAPE SEAL in it, forming an effective system for cracks – whether they have movement or not. And if the movement is serious, it must be previously stapled and filled with a structural repair mortar, such as PROPAM REPAR TECHNO.

The stone tile removed to lay PROPAM IMPE FLEX plus the elastic band can be re-bonded with our PAM® ECOGEL FLEX adhesive, and the grouting can be finished with our legendary BORADA® EPOLUXE, a bi-component composed of silica sands.

PROPAM IMPE FLEX is also suitable for the complete renovation of the pool shell without the need to remove the old tile, if it is well adhered, acting as a double waterproofing and bonding bridge for the installation of the new liner.

With them, you will save water and money, avoiding cracks and leaks in your pool. Come to consult us and we will offer you the technical advice you need!

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