The contractors working to stabilise the Castleblayney Market House have requested an extension of time to complete additional work.
Under the guidance of a structural engineer and conservation architect, the contractor was appointed in May to remove the roof of the building and install structural supports.
It was originally estimated that the work would take eight weeks.
The road connecting Main Street and Market Square is expected to be opened later this week, with the remaining cordons being removed by the end of the month.
Monaghan County Council has apologised for the ongoing closures but said it’s in the interest of public safety.