One of the earliest clues is usually a subtle, persistent damp patch that doesn’t make sense. Maybe paint is bubbling in a small area, plaster feels slightly soft, or there’s a faint discoloration on a wall or ceiling that slowly grows. Sometimes the first sign is a musty smell that doesn’t go away, especially in corners or near wardrobes pushed against walls.
Another giveaway is your water meter or bill. If you’re sure all taps are off, but the meter is still moving, or your water usage jumps without any lifestyle change, it often means water is escaping somewhere out of sight. In apartments, you might also hear a faint hissing sound in the wall when everything is off.
What people often do wrong is to repaint over dampness without finding the source. The patch looks fine for a few weeks and then returns. That’s your signal: the problem is inside the wall or floor, not on the surface. At that point, getting a plumber to trace the line and fix it is much better than living with hidden damage.
