Thermal imaging is sometimes confused with X-Ray vision. When an inspector uses a thermal camera to view a surface, the camera does not see thru or behind the surface, but instead measures the surface temperature. The surface temperature of the building interior components can be different from place to place if there are air or water leaks behind the visible material. The IR (infre-red) camera will display the temperature differential between areas on a color monitor (video screen) and produce the appearance of being able to see thru the wall, ceiling, or floor.
In fact the camera does not see thru the building components but merely displays a visual record of the surface temperature differential. The thermal camera will not indicate the cause of the problem. This is why a good thermographer will use other tools such as a moisture meter to assist in the determination of cause. For example, the moisture meter may show a wet surface, indicating a water problem, or it may indicate no moisture which will help the inspector determine that an air leak or insulation problem exists.
In some of the pictures shown on the home page you can see the cameras ability to demonstrate an in-floor radiant heat system that is only partially functional. Those pictures were recorded in a 2 million dollar condo located in Breckenridge Colorado where the prospective buyer wanted to assure that all heating components were functional. The thermal inspection revealed that in fact several heating loops were clogged and one zone valve was not working at all.