Building Inspection: Thermal images are commonly used in buildings to evaluate how heat flows through walls and surfaces. Insulation is a very important aspect of this transfer. Poorly insulated walls allow convection and radiation heat within the wall cavity. Wet, Damaged, or settled insulation is also visible with thermal images because of the differences in heat transfer. Other moisture issues such as humidity, condensation, and water leaks can affect all areas of a structure. Water damage is an problem that grows with time and is best caught early.