New Zealand's biggest construction company has revealed it sent faulty concrete to about 35 building sites, including the country's biggest ever road project.
Last week, Firth, which is owned by Fletcher Building, was forced to stop production of concrete at an Auckland plant after testing found it to be weak.
The Transport Agency has confirmed some of the concrete was used on the $1.4 billion Waterview Connection project.
Its Highway Manager Brett Gliddon said a part of a ramp would need to be repaired as well as retaining walls, footpaths and crash barriers.
He said the fault would not delay the early 2017 opening of the road.
Firth's General Manager Andrew Moss said about half of the 35 building sites will need repair work done.