Foam Insulation Under Pool: Choosing the Right Thickness

Cellular plastic under the pool can reduce heat loss and create an even base, but the material and thickness must be adapted to the structure and load. The guide explains what you should check before installation.

Understanding the role of insulation foam in pool installations:

Before we go into the specifications for the thickness of the cellular plastic, let us first understand why cellular plastic is a preferred choice for pool underlay:

Thermal insulation

• Cellular plastic, a type of expanded polystyrene (EPS), is well known for its outstanding thermal insulation properties. By placing cellular plastic under the pool, heat loss is minimised, ensuring that the pool water retains heat more effectively. This contributes to a more energy-efficient pool and lower heating costs.

Lightweight and durable

• Cellular plastic is lightweight, making it easy to handle during installation. Despite its lightness, it is durable and can withstand the weight and pressure exerted by the pool structure over time, providing a stable base.

Resistance to moisture

• Foam plastic is inherently resistant to moisture, which prevents water absorption. This property is important for maintaining the structural integrity of the substrate and avoiding potential problems related to water damage, such as mould growth and material deterioration.

Versatility during installation

• Cellular plastic boards can easily be adapted and cut to fit all pool shapes or sizes. This versatility simplifies the installation process and ensures a snug fit beneath the pool structure, which is crucial for effective insulation.

Determining the optimal thickness:

The optimal thickness of foam insulation under a pool depends on various factors, and it is important to consider these factors to achieve effective insulation. Here are some key considerations:

Climate zone

• The climate in your region plays a major role in determining the required thickness of the polystyrene foam base. In colder climates, where the ground is more prone to freezing, a thicker layer is usually recommended to prevent heat loss and protect the pool structure from ground movement caused by freezing.

Pool type and size

• The pool's size and type affect how much heat it loses to the ground. Larger pools and those with a greater surface area may require a thicker expanded polystyrene underlay to retain the water temperature effectively, as they have a larger contact area with the ground.

Type of pool installation

• The pool's installation method also affects insulation needs. In-ground pools, for example, can benefit from thicker insulation compared with above-ground pools due to their direct and constant contact with the ground, which increases the risk of heat loss.

Local building regulations

• Check local building regulations and codes, as they may specify certain insulation requirements for pools. Complying with these rules ensures adherence to safety and building standards and contributes to the pool’s long-term durability.

Benefits of sufficient foam insulation thickness:

Reduced heat loss

• The main purpose of foam underlay is to minimise heat loss from the pool to the ground. Sufficient thickness creates an effective thermal barrier and helps the pool water retain heat for longer periods, resulting in a more pleasant swimming experience.

Energy efficiency

• A well-insulated pool is more energy efficient. It reduces the workload on pool heater and other heating systems, resulting in lower energy consumption and operating costs over time.

Extended swimming season

• With effective insulation, your pool can maintain comfortable water temperatures even during colder seasons. This extension of the swimming season enhances the overall usability and enjoyment of your pool, providing more time for relaxation and recreation.

Prevention of ground freezing

• In colder climates, a thicker layer of cellular plastic acts as a buffer against ground frost. This helps prevent the formation of ice beneath the pool and protects the pool structure from potential damage caused by ground movement during freezing and thawing.

Structural protection

• The compressive strength of the EPS adds an extra layer of protection for the pool structure. It helps to distribute the pool's weight evenly and minimises the risk of damage due to uneven ground subsidence or settling over time.

Moisture regulation

The moisture-resistant properties of polystyrene help maintain a dry and stable environment under the pool. This prevents the development of mold, mildew, and other problems related to excessive moisture, extending the pool’s lifespan.

Installation guidelines for foam underlay:

Surface preparation

• Ensure that the ground beneath the pool is level, compact, and free from debris. Any irregularities in the ground may affect the performance of the polystyrene foam base and, in turn, the stability of the pool.

Customized cut

• Measure and cut the polystyrene sheets to fit the shape and dimensions of your pool. Note the corners and curves and ensure an exact fit to avoid thermal bridging.

Warehousing

• Install multiple layers of bubble wrap if needed, especially in areas with harsh winters. Layering improves insulation and provides extra protection against heat loss, maximizing energy savings.

Joint sealing

• Use adhesive or tape to seal the joints between the polystyrene insulation boards. This helps create a continuous insulation barrier and prevents thermal bridging, where heat can escape.

Secure placement

• Secure the polystyrene foam underlay in place to prevent shifting or displacement over time. This can be achieved using adhesive, tape, or other suitable fastening methods, ensuring that the insulation remains intact.

Consideration for pool equipment

• Ensure that the foam underlay extends beneath pool equipment such as pumps and filters. This helps maintain consistent insulation across the entire pool area and prevents heat loss from pipes and other equipment.

Maintenance and troubleshooting:

Regular inspections

• Inspect the foam underlay regularly for any signs of damage, displacement, or deterioration. Address any issues promptly to maintain optimal insulation and prevent more serious problems.

Drainage considerations

• Ensure there is proper drainage around the pool area to prevent water accumulation under the expanded polystyrene. Excess water can compromise the insulation's effectiveness and lead to structural problems.

Repair damaged areas

• If any part of the foam insulation base is damaged, repair or replace those sections immediately. Damaged insulation can lead to increased heat loss and potential structural issues, as well as reduce the pool’s lifespan.

Adjustment for changed circumstances

• Consider adjusting the thickness of the foam underlay based on changes in the climate or patterns of pool use. This flexibility ensures continued effectiveness in maintaining the water temperature and optimises energy consumption over time.

Conclusion

Summary: the thickness of the foam underlay beneath your pool is a crucial factor in optimising insulation and ensuring efficient pool operation. By carefully considering the climate, pool type, and local regulations, you can determine the appropriate thickness for your specific needs. Investing in a sufficiently thick foam insulation underlay offers a range of benefits, from reduced energy consumption to an extended swimming season and structural protection. Follow the correct installation guidelines, carry out regular maintenance, and enjoy a well-insulated pool that provides comfort and enjoyment for many years to come.