MORPETH bridge roadworks will begin on Monday for delayed maintenance work that will run into next year.
The bridge will close entirely for one night next month. A date is yet to be determined.
The broader works will run 6am to 4pm Monday to Thursday for nine months as efforts to keep the state heritage timber-truss bridge in shape continues.
Transport for NSW regional director north Anna Zycki said the work was necessary to ensure the bridge remained safe.
"Work will include repainting the bridge, installing a maintenance monorail to the underside of the deck and repair to some truss elements to ensure it continues to serve and connect the community and visitors," Ms Zycki said.
Drivers will have to obey a 40km/h speed limit, while a barge under the bridge used in some of the maintenance will require partial closure of the river to marine traffic.
A four knot speed limit will be in force.