Waterproofing in swimming pools is done in different methods. This differs from the use of liners, or to coat the bottom of a pool with concrete or plaster. Waterproofing may be achieved by using paints, liquid membranes for floors and ceilings, and resilient paints.
Different methods of doing waterproofing in swimming pools
Waterproofing in swimming pools is done by placing vinyl or polymer liners over the floor, walls, or ceilings. Vinyl liners can be placed directly on concrete (although some prefer that it has a cementitious skim coat first), but they must be placed properly. Vinyl liners have to be installed slowly, keeping the wrinkles from forming in the liner. If vinyl liners are to be placed on top of softened concrete, another method is used: a thin cement plaster layer must first be spread over the entire pool before placing the liner.
The use of cementitious waterproofing in swimming pools has declined significantly since the 1950s. This is because many of these older cementitious waterproofing methods proved to be either more expensive or have other problems, such as the need to repair cracks in the waterproof coatings after a few years of use.
However, some older swimming pools were built with concrete floors and walls, including “gunite” (shotcrete) and poured-in-place (concrete) wall liners that are still functioning satisfactorily today. If crack repairs are done on schedule and only when necessary, pool owners can operate these pools almost indefinitely without needing major renovations or new construction. One advantage to this method is that the lining materials are normally nonreactive; they will not leach chlorine or other chemicals that can give rise to eye and skin irritations or aggravate existing health problems. There are also no seams for water to penetrate, as in tanks, lined with plastic sheets.
What are the drawbacks of concrete pools?
The major drawback of concrete pools is their high cost. In addition, poorly constructed installations can be unsightly and may create safety hazards if the walls are not straight or have inadequate drainage planes around them. The latter problem has long plagued the operation of outdoor gunite pools; there were many instances of children falling into wet depressions between the pool’s wall panels and suffocating before someone noticed they were missing from a group playing nearby.
The one method that you can rely on
The best waterproofing for swimming pools is a complete lining made out of one membrane. In the last few years, however, new research has resulted in low-cost lining systems that are easy to apply and capable of lasting many decades with minimum maintenance.
For example, several manufacturers now sell inexpensive pool liners composed of long rolls of polyethylene plastic sheets reinforced by thin glass fibers or tiny glass beads. These linings are available in various colors and can be cut with scissors to fit the contours of any irregularly shaped swimming pool. They must be overlapped on all seams; otherwise, they will separate under the stress of water pressure and leak like a sieve. After installation, they should never be punctured or burned.
The second-best alternative
GRP lining in swimming pools is also the best solution for pool owners who can no longer or do not want to spend much time and effort maintaining their pools, while they would still like them to look nice.
GRP linings are UV-stabilized, which means that the whole lining will lose its color only after many years of sunlight exposure. The fading process is similar in appearance to rot as it shows on wood. However, polymer liners age very gracefully this way and develop a patina that more than compensates for any loss of coloration through sunlight exposure.
GRP pools are also extremely easy to clean – ordinary garden hose water pressure will remove algae accumulations within minutes – without using expensive chemicals.
So the conclusion is that nowadays, both cementitious and GRP lining are extensively practiced as a waterproofing system for swimming pools.