Ground Subsidence in Swimming Pools – Causes, Solutions, and the need for a Structural Engineer Report
Swimming pools are a popular feature in many homes, offering a perfect place for relaxation and recreation. However, when the ground beneath a pool subsides, it can lead to significant structural issues that compromise the safety and usability of the pool.
Understanding the causes of ground subsidence, the potential problems it can cause, and the necessary steps to address these issues is crucial for pool owners.
Causes and Impacts of Ground Subsidence in Swimming Pools
Ground subsidence occurs when the soil beneath a structure shifts or settles, often due to changes in moisture content, soil composition, or the presence of expansive soils. In the context of swimming pools, this can be particularly problematic because:
Uneven Settling
Pools require a stable, level base. If the ground subsides unevenly, it can cause the pool structure to crack, the pool surface to become uneven, and potentially lead to water leakage.
Structural Cracks
Subsidence can exert stress on the pool walls and floor, resulting in cracks that can compromise the integrity of the pool and lead to water loss.
Damage to Plumbing and Fixtures
As the ground shifts, the plumbing and fixtures connected to the pool can be displaced or damaged, leading to leaks and other malfunctions.
Safety Hazards
Cracked or uneven pool surfaces can pose a risk of injury to swimmers, making it essential to address these issues promptly.
Crushed Swimming Pool
This pool at Raby Bay was crushed by hydrostatic pressure. Causes: fiberglass pool, no hydrostatic valve, high water table, pool was emptied and rising water table lifted and crushed the pool.
The Need for a Structural Engineer Report
When ground subsidence is suspected or detected, obtaining a structural engineer report is a critical step. Here’s why:
Accurate Assessment
A structural engineer can provide a detailed evaluation of the extent of the subsidence and its impact on the pool structure. This includes identifying the causes of the subsidence and assessing the severity of the damage.
Guidance on Repairs
The report will offer recommendations on the best course of action to repair the damage. This ensures that any remedial work is both appropriate and effective.
Preventive Measures
Beyond repairs, a structural engineer can advise on preventive measures to minimise the risk of future subsidence, such as improving drainage or reinforcing the pool structure.
Potential Repair Solutions
The specific repairs needed to address ground subsidence in swimming pools depend on the severity and nature of the problem. Common solutions include:
Foundation Stabilisation
One of the primary solutions for subsidence is stabilising the ground beneath the pool. This can involve injecting grout or other stabilising materials into the soil to fill voids and prevent further settling.
Underpinning
Similar to buildings, swimming pools can be underpinned to stabilise the foundation. This involves extending the foundation to a deeper, more stable layer of soil or rock.
Crack Repair
Cracks in the pool structure can be repaired using specialised epoxy or polyurethane injections, which seal the cracks and restore the pool’s integrity.
Re-Leveling the Pool
In cases where subsidence has caused the pool to become uneven, it may be necessary to re-level the pool. This can involve adjusting the pool’s supports or even rebuilding parts of the pool shell.
Plumbing Repairs
If subsidence has damaged the pool’s plumbing, these systems may need to be repaired or replaced to prevent leaks and ensure proper functionality.
Conclusion
Ground subsidence can pose serious risks to the integrity and safety of swimming pools. Addressing these issues promptly with the help of a structural engineer ensures that the necessary repairs are made correctly and effectively.
If you suspect ground subsidence under your pool, obtaining a structural engineer report is an essential first step in safeguarding your investment and maintaining the safety of your pool area.
Contact Forensic Engineers for expert advice and comprehensive structural assessments to ensure your pool remains a safe and enjoyable feature of your home.
