How does Infrared work for finding flat roof leaks?
A; “Thermal Capacitance” is at play here too. It is sort of like thermal inertia. Heat always moves toward cold. Wet materials will hold the heat of the day much longer than the dry portions of the roof. Roof scans are done during the early evening hours, typically 1 to 2 hours after sunset on a clear night. Since the night sky offers a very strong “cold”, the roof starts to give up its heat to the cold night sky. Those areas that are saturated will hold the heat longer and show up on a thermal scan.
