Roofing
A common application is the evaluation of built-up roofing systems. Leaks in the roof allow moisture to become trapped in the insulation below.  Solar loading of the trapped moisture causes the temperature to rise. This area will retain heat for longer periods when compared to dry insulation. This concept allows for accurate location of the affected areas. This inspection will take place shortly after sundown. The areas are marked using cans of spray paint. This practice often reveals that only small portions of the roof are in need of repair. A high payback occurs when only the wet area of the roof are repaired rather that having to repair an entire roof.
 

   Building Envelope
Outside of buildings can be evaluated for energy loss. These inspections are best performed during the time of the year when the inside temperature is quite different from the outside temperature. This creates a greater delta between the inside and outside to maximize results of the inspection. This inspection can reveal energy loss around window and door seals, insulation voids, and construction defects. From the inside, insulation voids are much more obvious. Moisture penetrated walls and ceilings can be identified before damage becomes extensive.