The Maungatapu Underpass is being closed at night to allow for a new paint job.
The section of Welcome Bay Rd where it meets with Turret Rd was closed from 7pm to 5.30am over the past three nights and will be close again this weekend while the bridge is being water-blasted.
An NZ Transport Agency spokeswoman said the paint on the pedestrian bridge needed to be stripped back and reapplied to repair a paint defect.
Moisture between the paint layers has caused the paint to bubble. This is a paint issue only, not a structural issue. Costs are being covered by the contractor, she said.
It is expected to take about a month to repaint the bridge but it will remain open at all times for walking and biking.
The spokeswoman said the work had been programmed for the school holidays to minimise disruption.
There will be another overnight closure on Sunday while the bridge is being water-blasted, and then again at the end of the work when the scaffolding is being removed.