This work will take place on Trinity Square, between Trinity Avenue and its junction with Mostyn Street, between January 12 and 17.
It will be carried out between the hours of 6pm and 6am.
Conwy County Borough Council said in a statement: “The noisiest work will be completed earlier in the evening to minimise disruption.
“We will have to close this road during the work. Diversions will be in place.
“There will be no parking on affected sections while we do this work. We will maintain pedestrian access at all times.”