Urgent industry change needed to combat poor construction - investigators

Concrete investigators are calling for mandatory independent quality assurance and pricing controls in an industry increasingly under pressure.

New imaging technology has revealed 1100 buildings nationwide have defective or missing concrete or reinforcing steel. Wellington company Concrete Structure Investigations, which carried out the research, said many buildings had not been constructed according to the plans.

Building Minister Jenny Salesa has ordered her officials to look into the validity of the findings.

Engineers are also making mistakes during construction, Auckland engineer Gordon Hughes said. More than half of the structures he had reviewed since inquiries began in 2003 have had "multiple, significant and serious mistakes".

"Many of the mistakes are the same or similar, even though they've been designed by different engineers, from different firms."

Despite comments made by Engineering New Zealand and implied in a recent paper in a journal from the Structural Engineering Society, SESOC, these were not small or sole-practice engineers, he said.

"All were engineers in mid-size and larger practices, including at least one from a multinational firm."

The engineers, and builders, are being thrown together on complex jobs where lowball quoting meant profit margins can be less even than two percent of the total quote.

Jane Roach-Gray of Concrete Structure Investigations said this is why there was not the time, skill or willingness to do a job right or remedy a botch-up.

"Busy consulting engineers, they're called up - even with best endeavours - at the last minute," she said.

"Constructions under pressure - they [contractors] will say, 'The concrete trucks waiting, you need to get here and check that these drag bars are gone in and they're connected'."

Engineers "end up turning up and not seeing everything that they need to see, or being told that things are being put in correctly and only seeing a small margin of them".

Junior engineers or engineers not familiar with the job might be called on to sign off the steel reinforcing, having checked work done by subcontractors operating far down the food chain where accountability was diluted, she said.

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