Building giant investigates projects over faulty concrete

A section of the Waterview Connection scheme has been identified as having used faulty concrete but transport chiefs stress there is no risk to motorists. Photo / Nick Reed

Work on up to 35 residential and commercial projects will need to be redone after faulty concrete was supplied and used in building work.

Firth, owned by Fletcher Building, has contacted customers after the company's quality control testing programme at its Auckland plant found some concrete did not meet product specifications. The discovery was made last Tuesday.

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Around 35 customers, involved in a mix of commercial and residential projects, have been affected. The projects range from multi-million dollar commercial ones, including Auckland's Waterview Connection project and the $42 million VXV3 commercial project in the Wynyard Quarter area, to backyard pathways and post holes.

"Customers were informed on the day the issue was discovered and Firth is liaising with each customer to assess the need for remedial action required on a case-by-case basis. Each site has been visited by a Firth representative to test the concrete and assess the need for remedial action. In approximately half of the cases no action will be needed and the concrete will remain in place," a Fletcher statement said.

Firth general manager Andrew Moss said action was necessary.

"Firth will do the right thing by its customers and replace the concrete where necessary as promptly and efficiently as possible," he said.

"Investigations indicate faulty measuring equipment at one Firth site is to blame and as such the issue is isolated to that site. The plant has since reopened," the statement said.

"Firth has a stringent quality control testing programme for all its concrete products. Each production site has daily testing and it was through this programme that Firth discovered the substandard concrete," it said.

A separate statement from Brett Gliddon, the NZ Transport Agency's highways manager, said its Waterview Connection project was one of the construction projects in Auckland that received some faulty batches of concrete from its supplier. He stressed there was no risk to motorists. "The faulty concrete was supplied to the project in late April. The Well-Connected Alliance is delivering the Waterview Connection for the Transport Agency.

"The overall integrity of the project in terms of quality and safety is not compromised. The quality control systems put in place by the Well-Connected Alliance helped identity the problem."

On-site investigations confirm a section of Ramp 4 on the Great North Road Interchange will have to be repaired. Some retaining walls, footpaths and crash barriers have also been affected.

Ramp 4 - now under construction - will be the second longest and the highest of the four interchange links, leading from the tunnels to the city and rising up to 23m high and extending 500m.

Mr Gliddon says the delivery of the faulty concrete will not have an impact on the project's overall programme of works, nor on its planned opening in early 2017.

The issue

• Firth concrete delivered to many big Auckland sites was too weak.

• Not enough cement had been added to the mix so the concrete would never harden to the required strength.

• Tests were carried out on the big sites to ensure engineering standards were met.

• Those tests identified the issues, which Firth and its parent Fletcher Building admitted.

• Auckland's Waterview Connection and the big new partially built VXV3 Wynyard Quarter sites are among those affected.