Pool waterproofing materials: selection and application

Recommendation points

• The main types of pool waterproofing
• The aesthetic component of choice
• Installation difficulties
• Influence on the communication device
• Performance characteristics

Ensuring the structural strength of the bowl is far from the only challenge when building a pool. When choosing a waterproofing method, there are several ways that differ in both the final appearance and the functional purpose and installation process.

The main types of pool waterproofing

In cross-section, the wall of the pool bowl is a rather complex “cake”, in which there may be several waterproof layers. Their composition, type and location are determined by the structural features of the walls and bottom, as well as the materials used for cladding.

So, when constructing the walls of a bowl made of sheet stainless steel, additional waterproofing is not required. A similar situation is with the coating with a polyvinyl chloride film: it creates an absolutely impermeable hydro-barrier, although in some cases additional waterproof layers can be arranged in case of mechanical damage to the external hydro-barrier or marriage when welding seams.

The most difficult is the process of creating a waterproof barrier when lining the pool from the inside with ceramic tiles. A wide range of construction chemicals is used here: from waterproof grout for joints to penetrating and injection compounds. In general, the installation procedure and the type of waterproofing for pools differ little from similar engineering solutions for basements and foundations. However, the composition of mastics and penetrates has additional inclusions that take into account difficult operating conditions, in particular, it is the increased water pressure and its high aggressiveness, due to the increased chlorine content..

We must not forget about external waterproofing. Waterproof barriers are arranged so as to prevent the penetration of water into the concrete mass with the subsequent activation of corrosion processes. However, for many pools, groundwater is also a hazard. To prevent their seepage, they mainly use roll materials, as well as special engineering structures: drainage systems, clay locks, etc..

The aesthetic component of choice

So, the device method and the choice of materials for waterproofing entirely depend on the desired appearance. Consider the three most popular types of interior surface finishes and related subtleties in waterproofing:

Option one – porcelain tiles. It is porcelain, since the usual one has too high water absorption. Since porcelain is installed using a special waterproof cement-based adhesive containing polymer binders, the surface must have high adhesion. For this reason, the use of internal coating waterproofing when laying tiles is not recommended..

The correct choice would be to inject the concrete bowl with microcement or cover it with penetrating insulation (Penetron, Drizoro, etc.). It is optimal to carry out these works before the completion of the curing of the concrete, that is, not later than 28 days after pouring. Hydrophobic impregnation is followed by priming with “Concrete-contact” and leveling plaster with the addition of latex plasticizers such as IDROKOL X20, Collaseal or on a polyurethane base. Alignment must be carried out with a tolerance of no more than 1.5 mm / m, otherwise the strict geometry of the tile will reflect all surface defects.

After the plaster has dried, it is moistened with an aqueous solution of potassium silicate until absorption stops, then the bowl is tiled. The thickness of the seams is much greater than when working with ordinary tiles; for grouting, a special waterproof filler is used, which has increased plasticity due to the high content of latex. In total, when laying tiles, three waterproof belts are equipped, not counting the outer.

Waterproofing and tiling of the pool: 1 – concrete pool bowl; 2 – penetrating waterproofing; 3 – primer “Concrete-contact”; 4 – leveling plaster layer with the addition of a plasticizer; 5 – potassium silicate solution; 6 – tile adhesive; 7 – tiles with waterproof grout

Option two – smalt. Glass mosaic helps to visually hide rather serious curvatures of the plane, so no plaster is applied over the concrete. Slugs and outgrowths protruding between the decks should be cut off and carefully sanded, cold seams should be cut off with a bentonite cord laying. The final leveling of the surface is carried out by means of latex mastic (Technonikol, Lacrysil), which can be applied with a sufficiently thick layer. If it is possible to attract competent specialists with professional equipment, it is recommended to pay attention to the coating of the bowl from the inside with polyurea, but in this case, preliminary leveling with plaster may be required.

Laying of smalt is carried out on latex glue, which has a good degree of adhesion to a wide range of hydrophobic coatings, except for roll coatings. Before laying the mosaic, the glue itself is wiped over the surface with a continuous layer, forming a second waterproof barrier. Grouting, as in the case of tiles, is carried out with highly plastic joint fillers.

Option three – film materials. A high-quality and well-soldered PVC film itself serves as an excellent insulator. Additional hydrophobization of the supporting structure is required only for high operating loads or large sizes of an artificial reservoir.

The preparation of the concrete surface is carried out by plastering without water repellents. In addition to roll materials for a hidden layer of waterproofing, it is most preferable to apply a two-component liquid rubber. Even if a gap appears in the film coating, the internal hydraulic seal will hold back the water pressure until the repair is carried out. Liquid rubber is the most expensive and technologically advanced method of waterproofing, but it is definitely worth the money and effort..

Installation difficulties

Almost all types of waterproofing have a special application technique. Only people with practical experience in using a particular material can take up work with confidence. The durability of the pool waterproofing in full compliance with the technology is from 30 to 50 years, however, there are a number of risk factors, including:

1. Use of untested and low quality materials.
2. Insufficiently thorough priming of the concrete structure.
3. Damage to waterproofing during finishing works.
4. Insufficient strength of the concrete bowl, its deformation and cracking

If the internal surfaces of the pool are fully accessible for hydrophobic treatment, then when applying the external one you have to work in cramped conditions. In the absence of a drainage system, it is the outer waterproof layer that becomes the weak point of the pool. Corrosion of concrete can be eliminated in one of several ways:

1. Penetration coating.
2. Injection from the inside.
3. Creation of a clay water-resistant castle.
4. Providing a sufficiently spacious pit for the technological coating of concrete with films and membranes with high-quality joining of sheets.
5. Using a concrete mix with zero water absorption.

Influence on the communication device

An obvious problem when waterproofing a pool is the complexity of the high-quality adjoining of the hydro-barrier to the elements of technical equipment and the water treatment system. Embedded for cavities for the installation of skimmers, nozzles, lanterns, drain and technical channels passing through the concrete must be equipped even before the concrete bowl is poured. It is categorically unacceptable to carry out slotting work for such concrete structures, vibration causes the formation of microcracks, which increase the filtration capacity of concrete.

The installation kits of the pool equipment have a hermetic connection with the fittings installed after finishing the finishing. It remains to ensure only a high-quality abutment of the hydro-barrier to plastic or metal. For these purposes, there are also several ways:

1. Rubber seals that ensure a firm pressure of the gasket to both surfaces.
2. Adhesive bitumen and rubber tapes, the type of which is chosen depending on the material of the general waterproofing.
3. Wrapping protruding mortgages with bentonite cord or tape.

The suitable method of waterproofing the abutments is determined both by the material of the main waterproofing of the bowl and by the recommendations of the manufacturers of hydraulic fittings.

Performance characteristics

During operation, the pool structure is exposed to significant loads, including the hydrostatic pressure of water, and soil displacement, and frost heaving forces. Waterproofing under these conditions is subject to destruction due to the fact that either itself is part of the concrete mass or is rigidly fixed to the walls of the bowl.

The most durable and, accordingly, durable coatings are considered to be liquid rubber, polyurea and latex coating mastics. Even when cracked, they do not break due to their high elasticity. It should be understood that the internal waterproofing of the pool is less susceptible to destruction: the materials are of the highest quality, there is no rigid soil support, the surface for application is carefully prepared.

The situation is completely different with external waterproofing. To exclude its damage, it is customary to use film or membranes that are not rigidly connected to the base instead of pasting and coating materials. To exclude the influence of solid soil particles, a soft sandy filling is arranged around the pool, which also favorably affects the safety of the hydrotechnical piping of the bowl..