Introduction to Pool Construction

Constructing a swimming pool is an exciting venture that not only enhances the aesthetic appeal of your home but also offers a refreshing oasis for relaxation and entertainment. Among the myriad aspects of pool construction, the choice of material plays a pivotal role in determining the pool’s durability, maintenance needs, and overall look. Concrete, known for its versatility and strength, stands out as a preferred material for building pools that last for decades.

Concrete pools are celebrated for their ability to be shaped into virtually any design, accommodating custom sizes, depths, and unique features like underwater benches and steps. This flexibility makes concrete an excellent choice for homeowners looking to personalize their backyard retreats. However, casting a pool requires careful planning, particularly in calculating the amount of concrete needed to avoid shortages or excess that could affect the project’s cost and timeline.

Understanding the basics of pool construction, the types of concrete pools, and the steps involved in casting can empower homeowners to make informed decisions throughout the building process. Whether you’re considering a compact plunge pool or a more spacious option for family and friends to enjoy, the journey begins with a solid foundation of knowledge and preparation.

Types of Concrete Pools

When considering the construction of a concrete pool, it’s essential to understand the different methods available. The two primary types of concrete pools are Shotcrete (or Gunite) and Cast-in-place concrete. Each offers unique advantages and challenges, influencing your project’s overall cost, duration, and finish quality.

Shotcrete or Gunite Pools: Shotcrete and Gunite are methods of applying concrete pneumatically through a hose at high velocity onto the pool’s surfaces. The terms often are used interchangeably, but the difference lies in the mixture’s moisture content. Gunite is dry until it reaches the nozzle, where water is added, while Shotcrete is pre-mixed with water before application. This technique allows for a highly durable shell, adaptable to any shape or design, making it ideal for custom pools. The application’s high velocity ensures the concrete compacts tightly around the reinforcement, reducing the risk of voids and ensuring a long-lasting structure.

Cast-in-Place Concrete Pools: This method involves pouring concrete into a wooden formwork constructed on-site, allowing the concrete to set and cure in place. Cast-in-place concrete is particularly suited for pools with a straightforward design or when building in locations where access is restricted. While this method offers a high degree of control over the pool walls’ thickness and can be less expensive than pneumatic application, it requires more time for formwork construction and curing.

Choosing between Shotcrete (or Gunite) and cast-in-place concrete depends on your specific needs, budget, and the pool’s desired shape and size. Both methods produce robust and leak-resistant pools but differ in application technique, cost, and construction time.

Determining the Size of Your Pool

The size and depth of your pool are crucial decisions that affect not just the cost and amount of concrete needed but also how the pool will be used and enjoyed. Small pools, often referred to as plunge pools or cocktail pools, typically range from 10×20 feet to 15×30 feet, with depths varying based on intended use.

Factors Influencing Pool Size and Depth:

  • Backyard Size: The available space is a primary constraint. Adequate clearance from property lines and space for surrounding amenities should be considered.
  • Budget: Larger pools require more materials, labor, and maintenance, increasing overall costs.
  • Intended Use: Exercise pools may need different dimensions and depths compared to pools designed for leisure or entertaining children.
  • Design Preferences: Some may prefer a deeper pool for diving, while others might opt for shallow areas for lounging.

Before finalizing the size, consider how the pool will complement your lifestyle, the landscape, and any future additions or changes to your outdoor space.

Calculating Concrete Needs

To estimate the amount of concrete required for your pool, you’ll need to calculate the surface area and volume of the proposed design. The basic formula for calculating the volume of a rectangular pool is:



For a small pool measuring 12×24 feet with an average depth of 5 feet, the calculation would be:

Volume=12×24×5=1440 cubic feet

Volume=12×24×5=1440 cubic feet

Since concrete is typically measured in cubic yards, you’ll convert cubic feet to cubic yards by dividing by 27 (the number of cubic feet in a cubic yard):

144027≈53.33 cubic yards​

≈53.33 cubic yards

This calculation provides a rough estimate of the concrete needed. It’s essential to factor in additional considerations, such as the thickness of the pool walls and floor, which can increase the total volume of concrete required.

Preparation and Foundation

A solid foundation is paramount for a long-lasting concrete pool. The process begins long before the concrete is poured, with careful attention to site preparation and foundation construction.

Steps for Preparing the Site:

  1. Excavation: The first step involves excavating the area where the pool will be located. This process must consider the pool’s dimensions and additional space for construction access. The excavation depth should account for the pool depth plus the foundation and pool floor thickness.
  2. Grading and Compacting: Once excavated, the ground must be graded and compacted to provide a stable base for the pool. Proper drainage around the pool area is also established during this phase to prevent water accumulation under the pool.
  3. Formwork Construction: For cast-in-place concrete pools, wooden forms are built to shape the pool walls and hold the concrete in place as it cures. Precision in formwork construction is crucial for achieving the desired pool shape and dimensions.
  4. Reinforcement: Steel reinforcement bars (rebar) are placed within the excavated area and formwork to strengthen the concrete, helping to prevent cracking and structural failure. The rebar is tied together to form a grid that will be encased in concrete.

The preparation phase is critical for ensuring that the pool will be level, stable, and capable of withstanding the pressures of water and soil. Skipping steps or poor execution at this stage can lead to significant issues down the line, including leaks or structural failure.

Mixing and Pouring Concrete

The concrete used for pools must be strong, durable, and water-resistant. Achieving the right mix and proper application is essential for the pool’s longevity.

Concrete Mix Ratios:

A typical concrete mix for pools might include one part cement, two parts sand, and three parts gravel, mixed with water to achieve a pourable but not overly wet consistency. The exact mix can vary based on local codes and the specific requirements of the pool design.

Pouring Techniques:

  • Shotcrete/Gunite Application: For Shotcrete or Gunite pools, the concrete is sprayed onto the pool’s surfaces over the reinforcement layer in a uniform layer, building up the pool walls and floor. This method requires skilled technicians to ensure even coverage and density.
  • Cast-in-Place Pouring: Concrete is poured into the prepared formwork, ensuring it fills all spaces and envelopes the rebar. Vibrating tools are often used to remove air bubbles and ensure the concrete is compacted tightly around the reinforcement.

After pouring, the concrete must cure for several weeks. During this time, it’s important to keep the concrete moist to prevent cracking, which can be achieved by covering the surface with wet burlap or a similar material.

Finishing Touches and Considerations

Once the concrete has cured, finishing touches can be applied to the pool’s surface. Options include plaster, tiles, or pebble finishes, each offering different aesthetics and durability. Plaster is a popular choice for its smooth surface and variety of color options, while tile and pebble finishes provide a more high-end look and increased resistance to chemicals and stains.

Longevity and Maintenance Tips:

  • Regular maintenance, including pH balancing, cleaning, and inspection for cracks, can extend the life of a concrete pool.
  • Addressing any issues promptly can prevent minor problems from becoming major repairs.
  • Seasonal care, such as winterizing the pool in colder climates, is also crucial for preventing damage.

Constructing a concrete pool is a significant investment in time, effort, and resources. Understanding the types of concrete pools, determining the appropriate size, accurately calculating concrete needs, and following through with meticulous preparation and finishing are all key to achieving a durable and enjoyable swimming pool. With the right planning and execution, a concrete pool can provide years of enjoyment and add value to your home.

This comprehensive guide offers a foundation for those considering the construction of a concrete pool, covering the essential steps from initial planning to final finishing touches. Whether embarking on a DIY project or working with professional contractors, informed decisions at each stage of the process can lead to a successful outcome and a pool that meets your needs and preferences.

This post was written by a professional at Pool Stop Custom Pools. has been building custom swimming pools in DFW area for over 20 year now. We has been consistently voted “Best Pool Company” in Rockwall by Living Magazine and its readers year after year. Our goal is to provide the community with the best design and construction technology available. Our team consists of the best and most educated professionals in the industry, across the board. Pool Stop offers a variety of services: New Pool Design & Pool Construction, Retail Pool Store, Pool Supplies, Water Testing, and Pool Cleaner Repair. Stop by today for a FREE Water analysis.