Thinking about adding a swimming pool to your property? It’s a fantastic idea, but it’s crucial to understand that pools are a significant investment, both in terms of initial construction and ongoing maintenance. Proper design and construction are paramount to avoid costly problems down the line. Let’s dive into the key factors to consider.

Essential Considerations Before You Build

Before any construction begins, there are several design considerations that must be addressed:

• Size and Shape: The size and shape of your pool should be dictated by its intended use and who will be using it. If you’re planning on using it for laps, a long and straight, yet narrow and shallow pool might be ideal. For aesthetic appeal, you could opt for a curved shape like a kidney or a freeform design.
• Depth: Depth is a crucial safety aspect, particularly if children will be using the pool. A shallow end of about 1 meter is adequate for children under 12. An average adult’s shoulder height is around 1.5 meters. If you plan to use it for diving, a deeper end will be required. Always consider the practicalities of depth, as even a small increase in depth can significantly increase the volume of water and therefore the maintenance costs.
• Access Points: Consider how people will get in and out of the pool, especially young children and elderly people. Steps built into the pool should be shallow enough for easy access. Stainless steel ladders are space-efficient, but can be more difficult to use.
• Lining: The pool’s lining is another element to consider. Tiles offer a long-lasting, low-maintenance, and visually appealing finish, but they are more expensive. Paint is a more cost effective option, but it requires a skilled application and may not last as long.

The Importance of Structural Engineering

A swimming pool is essentially a water container, and water is very heavy. A small 4x5x1.6 meter pool will hold 32 metric tons of water. Thus, it’s imperative that the pool is structurally sound to prevent any cracks or ground movement.

• Professional Design: Pools must be designed by civil or structural engineers who can calculate the stresses and strains the structure will be subjected to.
• Ground Support: The ground around the pool will offer support, and the nature of the ground impacts the pool’s structure. If the ground is firm like clay, the pool will likely have ample support. However, if the ground is light, porous, or has been affected by water, air voids might exist, leading to stress points in the pool. If the pool is built against a hillside, proper engineering design is absolutely necessary.
• Reinforcement: The walls and base of the pool must be sufficiently rigid to hold the water without flexing. Flexing can cause the concrete to crack. Reinforcing steel should be designed correctly and embedded in dense concrete with at least 6cm of coverage to prevent rusting. Two layers of steel mesh are recommended to prevent sagging.

Construction: Ensuring a Watertight Result

Competent construction is just as important as good design.

• Competent Contractor: Always hire a contractor who understands reinforced concrete.
• Single Pour: The concrete shell, including the walls and bottom, should be cast as a single piece of concrete. If the bottom is poured first and the sides later, the joint is likely to leak.
• Concrete Density: Use a vibrator when pouring the concrete to remove air bubbles. Do not rely on poking the concrete with an iron bar, as this is not effective. Concrete should be strong, with a K300 rating.
• Pipes and Drains: Ensure the water circulation pipework and the drains at the bottom are installed before the concrete shell is cast. The plumber must ensure all the joints are securely glued as you won’t have the ability to repair leaks after the pool is complete.
• Electrical Safety: Conduits for pool lighting must be designed and built into the pool shell in a manner that ensures safety, is maintainable, and leak-proof. Pool lighting must use low voltage (12 volts).
• Waterproofing: Once the concrete is cast, it needs to be lined with a waterproofing agent and then a cement screed before the final layer of tiles or pool paint. In the bottom of the pool, the screed shapes the bottom of the pool so the water flows to the drains.

Leaks: A Serious Concern

A leaking pool is difficult to repair. It is essential to build the pool properly the first time. Water can easily seep through the tiles and find a crack in the cement screed and then into the concrete. Once the water escapes, it is very difficult to determine where the initial leak started.

Can Leaks Be Repaired?

Some leaks are repairable if you know what you’re doing.

• Check for evaporation: Keep in mind that evaporation will decrease the water level and could be mistaken as a leak.
• Pipe Leaks: Leaks in pipes or where pipes pass through the concrete can be repaired. Pump room or balancing tank leaks are also usually straightforward to repair.
• Cracked Shell: If the pool shell itself is cracked, it’s the most difficult to address. If a hole has not been sealed it may be repairable, but cracks due to poor construction are usually beyond repair. The only possible solution is to cast a new pool inside the old one, or to demolish and start again.

Building a pool requires careful planning, skilled construction, and an understanding of the potential issues. By focusing on high-quality design and construction, you can avoid major headaches and enjoy your swimming pool for many years to come.