If the crack is noticeably deeper than the plaster or paint, that could also be problematic, as could cracks close to windows or doors, or spanning form where the wall meets the ceiling.

Montreal Metro's Green line is closed between Lionel-Groulx and Frontenac stations for an indefinite period, after a water leak led engineers to detect cracks in the vaulted ceiling between Berri ...

CBC LiteMontreal Metro's Green line shut down after cracks detected in tunnel ceiling CBC News | Posted: April 24, 2023 4:33 PM | Last Updated: April 25, 2023 Water leak leads engineers to find ...