Smell
A musty odour that comes and goes with humidity usually indicates damp organic material somewhere in the room, even without a visible stain.
Surface changes
Paint bubbling, tape seams lifting, nail pops and swelling trim all suggest movement in the material behind the finish.
- Discoloured patches that darken in humid weather
- Flooring that cups, gaps or feels spongy
- Grout and caulking that keeps failing
- Doors that begin to stick in one frame
Utility clues
An unexplained increase in water usage often points to a supply leak running continuously somewhere out of sight.
Confirming it
Thermal imaging highlights suspect areas and moisture meters confirm whether the material is actually wet, which avoids opening walls unnecessarily.