Forge Road Riverbridge in Machen will be closed for eight weeks from September 15 to carry out essential maintenance works.
As the bridge is narrow, Caerphilly County Borough Council has said it will have to be completely closed to traffic and pedestrians in order to carry out the work.
The adjacent footbridge will remain open to pedestrians but vehicles will be diverted via a signed diversion route through Draethen.
There will be additional temporary passing places installed along Rhydygwern Lane.
To try and shorten the length of time the bridge is closed, the contractor will be allowed to work until 7pm weekday evenings and on Saturdays and Sundays 8am until 4pm. This is longer than normal but the council has said it wanted to strike a balance between any disruption caused by noise against the difficulties caused by the road closure.
Anyone with concerns over access can contact the council on 01495 235323 or email engineering@caerphilly.gov.uk.
The contractor’s liaison officer for the project is Georgie Dixon who can be contacted on 03300 412 183 with any queries in relation to the work.