An engineer says the complaints authority should not have ordered an insurer to pay a disputed swimming pool claim that was declined because a hydrostatic pressure exclusion referred to “gravity”.

As insuranceNEWS.com.au reported, a homeowner lodged a claim after her pool was lifted out of position following heavy rain at the start of the year.

Allianz declined the claim, saying the damage was caused by hydrostatic pressure, which it defined as “pressure exerted by a fluid due to gravity”. But the Australian Financial Complaints Authority said as the pool was moved upwards, the “force was not being exerted due to gravity”, and the claim should be paid.

This was despite policy documents including an example of hydrostatic pressure lifting a pool, which matched the complainant’s experience apart from the fact her pool had not been empty at the time.

Simon Fagg, principal forensic engineer at NSW-based Fair Engineers, told insuranceNEWS.com.au that, based on the information in the published AFCA determination, the decision is “clearly incorrect”.

He says Allianz’s definition of hydrostatic pressure is accurate, and that fluid pressure created by gravity can “act in all directions”.

“In fluid mechanics, the total energy or head of water is made up of two components – a gravity head and a velocity head,” he said. “In a groundwater environment, the velocity head is essentially zero.

“This means that the pressure water or an incompressible fluid will apply at any depth is the weight of the water above that point. This weight can either be directly above the point, as in a water tank, or horizontally away from the water above, as is typical in a pipeline or on the underside of a pool structure.

“So the policy definition of ‘pressure exerted by a fluid due to gravity’ technically describes the fluid pressure created by gravity of the fluid above the level where the pressure acts (i.e. the base of the pool). This pressure will act in all directions (i.e. up, down and sideways).”

Mr Fagg says AFCA’s comment that the damage was caused “by water pushing the pool upwards, against the force of gravity” indicates that those making the decision “have no technical understanding of fluid pressures”.

“The water pressure pushing the pool upwards was created by the gravitational weight of the water on the sides of the pool,” he said.

“The reason the pool would move is that once the total force created by the water pressure exceeds the weight of the pool structure, water within the pool and a small amount of friction between the side of the pool and the soil, it will be displaced upwards.

“Ships float on the basis of the same principal. The water pressure on the hull of the ship is the gravitational weight of the seawater beside the ship.”

Mr Fagg says Allianz should not abandon its definition of hydrostatic pressure because “it is correct from an engineering technical perspective”.

“While it may be possible to add to the definition to make it clearer to laypeople in some form, the technically correct basis should remain,” he said.

“Simply, the AFCA decision is incorrect and should be appealed.”

An AFCA spokeswoman told insuranceNEWS.com.au the authority does not comment on individual cases or decisions, and there is no avenue for appeal.

“AFCA determinations are binding on member firms if the complainant accepts the decision,” she said.

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