Riser
A riser leak is a vertical event. One suite is not the whole story.
Supply and waste stacks serve many floors. A failure can show in a closet on 12 and a ceiling on 9. Occupants arguing about one bathroom miss the pipe they share.
List every suite that saw water, with times.
A column of stains is a riser clue.
Access to closets and shafts beats opening living-room walls.
The corporation has to coordinate those doors.
Do not let each floor hire its own plumber into the same shaft.
One investigation, one finding, then repairs.
Questions people ask
If my suite is dry, am I done?
Not if the riser that serves you is the suspect. The manager should still be in the loop.
Is a riser always common property?
Often, but documents decide. The physical finding should still name the stack.