Swimming pool distortion when empty of water

Causes

Soil/ground water pressure on pool which is greater than weight of empty pool

Common

Listed under: Section, swimming pools

Cause

Soil/ground water pressure on pool which is greater than weight of empty pool

Repair

  • as a general rule, in-ground swimming pools should only be completely drained of water for reasons such as deep cleaning every 5 years or for major repairs. Once the cleaning/repairs have been done, refill the pool as soon as possible. If you plan to empty your pool it is a good idea to ask the supplier/installer for advice about how to do this safely
  • many types of pool depend for their structural integrity on water pressure in the pool exerting force against the surrounding earth and groundwater. If the pool is left empty for an extended period, pressure from the surrounding earth and water can result in cracks and damage to the pool
  • some pools are designed with ribbing or reinforcing to help strengthen the pool structure and reduce the risk of this type of damage
  • because the weight of water in the pool also holds it down, leaving the pool empty for long periods may result in the pool being pushed upwards under pressure from surrounding wet soil. The risk is greater in areas with high water tables where there is greater hydrostatic pressure on the pool
  • whether the pool can be repaired depends on the degree of damage it has sustained. Contact the original supplier/installer or an experienced specialist pool repair company for advice
  • in some circumstances, installing a new pool liner inside the existing pool may be an option
  • if the ground around the pool does not easily drain after heavy rain, consider installing a drainage system. This will typically involve slotted drainage pipes under the surface. Flexible and solid proprietary products are both readily available. These should be installed in trenches lined with gravel and should slope downwards approximately 10 mm for every 100 mm of length. The excess water should drain to a soak hole or a stormwater system. If you are building a new soak hole, or plan to make a new connection to your stormwater system, consult your local council first

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