A road builder says rusting bolts on two new viaducts on the Pūhoi to Warkworth motorway have all been fixed.
The Pūhoi-to-Warkworth Ara Tūhono motorway north of Auckland. Photo: Waka Kotahi screenshot
Motorists are already using one of the viaducts, though the whole motorway itself won't open till next year, more than a year behind schedule.
The NX2 joint venture said a "very small number" of galvanised bolts or nuts were damaged when they were tightened.
Quality control process picked this up.
"It is common for the corrosion protection system to incur some damage during transportation and installation, and to require touch-up repairs," NX2 said.
They had been replaced, or new corrosion protection had been put on them, with that work independently tested and verified, it said.
"The cost of remediating the coatings to the bolts is born by the subcontractor that erected the steelwork."
All the fastenings were fit for purpose and there was no safety risk, it said.