An upmarket Walsh Bay apartment block could come down like a ''house of cards'' within a decade because seawater is severely damaging two car parks in the foundations, a car park owner has claimed.
Greg Hawes said the developers of the Towns Place block at Walsh Bay - Mirvac and Transfield - had dismissed the damage as ''cosmetic maintenance''. But he said two experts had found the problems were ''very serious''. Repairs worth $4 million were needed on the commercial car park. The adjoining two-level residential car park needed $2 million of repairs.
The car parks sit below the 65-unit Towns Place block, completed five years ago. Apartments have sold for more than $3.5 million. Two Mirvac executives are believed to live in the building.
In the commercial car park, the Herald was shown water damage, which was identified in May when Mr Hawes and his partners tried to sell the commercial car park.
A 68-page report on the car park's problems by the building consultants Washington Brown, presented to Mirvac in November, states: ''Although the structure has not been structurally compromised at present, if remedial repair works are not undertaken in the near future, the rate of deterioration will rapidly increase and the durability and the strength of the [concrete] slabs will be compromised.''
A Hyder Consulting report on the residential car park found: ''The reinforced concrete slabs, beams and columns along the northern side of the car park appear to have been exposed to high levels of chloride due to ingress of groundwater into the car park.''
The groundwater appears to be from the harbour. Mr Hawes and his partners are preparing to take the matter to the Federal Court, claiming Mirvac and Transfield have built the wrong type of car park.
''The car park's been built to a standard that would work quite well if it was in Tamworth, it just doesn't work well next to Sydney harbour,'' Mr Hawes said.
''It's not built to withstand seawater penetration … the chlorides are rusting the metal inside the concrete and it's just causing rapid deterioration now.''
Neither of the reports mention potential damage to the apartments but Mr Hawes said the problem had worsened in the past year and the building above was being compromised.
''Ultimately the concrete will sag, which will then affect the foundations of the building and ultimately they wouldn't meet Australian standards to habitable residences and could ultimately be condemned,'' he said.
The chairman of the Towns Place owners group, Geoff Stirton, said the apartment owners were aware of the problems but did not want to comment until they had met the developers. ''If the issues are as we suspect, then we're very concerned.''
When contacted on Thursday, the chief executive of Mirvac NSW development, John Carfi, said he was unable to comment because there would need to be a ''consensus'' on any response with Transfield.