The industry ombudsman has backed an insurer that denied a car damage claim after water entered through a rusted sunroof drain.

The Australian Financial Complaints Authority found Prevail Insurance was right to rule the cause was long-term deterioration rather than a storm event, as claimed.

The Range Rover’s owner said unusually heavy rain in August last year and a major storm the next month caused water to enter the vehicle, leading to electrical and interior damage that left the car a total loss.

But assessors – including the policyholder’s own consultant – agreed corrosion had developed over several years.

Prevail’s assessor said the vehicle’s sunroof drains had “rusted off”.

A mechanical engineer also found the passenger-side drain tube had detached from the sunroof frame.

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The owner’s consultant argued the claim should be accepted anyway, because the policyholder serviced the vehicle regularly. Checking sunroof drains was not part of Land Rover’s scheduled servicing requirements.

AFCA says the policy covered accidental damage caused by a “sudden and identifiable event” but excluded normal wear and tear, and rust or corrosion.

It rejects the argument the September storm caused the loss.

“The expert reports indicate the rust developed over several years,” the ombudsman said.

Because none of the reports indicated how long the roof was leaking before the claim, AFCA considered whether the drain tube disconnected suddenly after gradually corroding. In theory, this could constitute a sudden event, but the ombudsman says it would not change the outcome, because the policy excluded damage caused by corrosion.

“If not for the rust, no damage would have occurred.”

See the ruling here.