The demolition of part of Llandudno hotel could affect the town's Extravaganza.
Work to demolish the failing part of the former Tudno Castle Hotel which it is understood will close of Mostyn Broadway and part of Vaughan Street, will begin on Tuesday April 18 and aim to finish before April 28, the day before the Extravaganza starts.
Contractors Bowmer and Kirkland who are working on the project said they would "will do everything we can to ensure that all roads are reopened before April 28".
A spokesperson said: "Historical movement in a wall structure has been found to be far more severe than initially assessed and we felt that an immediate road closure was prudent to protect members of the public, should there be further instability and risk of collapse onto the road outside the site.
"Building Control and the Highways Authority were consulted and the closure and appropriate traffic diversions were agreed. We are monitoring the traffic situation to ensure the diversions are working effectively.
"Unfortunately two thirds of the façade on Mostyn Broadway cannot be saved, so we will demolish the failing part of the structure and rebuild it.
"Demolition is due to start week commencing Tuesday April 18. We are aware that there is an extravaganza in the town at the end of this month and will do everything we can to ensure that all roads are reopened before April 28.
"We appreciate that this road closure over the Easter weekend will cause significant inconvenience and for that we apologise, but the safety of the public is our number one priority."