Moisture damage is the most common form of deterioration for a building. Air leakage can cause condensation to form within walls, floors, or ceilings. Wet insulation takes a long time to dry and becomes a prime location for mold and fungi.
Scanning with a thermal imaging camera can locate moisture that creates an environment conductive to mold. One might smell its presence, but not know where it is forming. A thermal survey will determine where moist areas are located that can lead to serious mold which can lead to health issues.
Moisture can be difficult to spot and the trick is to make the construction change temperature. Materials with moisture will then be clearly visible as they change temperature much slower than dry materials. Where other methods only measure the temperature in one spot, thermal imaging cameras can scan an entire area rapidly.