Flat roofs or roofs with a low slope are especially prone to moisture contamination, since the lack of space under the roof retards proper air flow and ventilation. (If you live anywhere with a decent amount of snowfall and know what an ice dam is, you understand what I'm talking about.) For government, commercial, and industrial roof owners, identifying moisture problems used to involve people on the roof using thermographic cameras to take multiple pictures of the roof. A roof area with moisture intrusion shows up as warmer than a dry area. Walk-on or rooftop examinations require many shots which then must be spliced together to build up a picture of the entire roof, and areas of importance are frequently missed.
Stockton Infrared Thermographic Services, Inc., AITscan Division, offers its RoofMoisture FindIR service, which uses military-type, high-resolution IR equipment flown over the roofs at night by ex-military pilots who specialize in low and slow night flying. Scanning at night means no reflections from the sun, lower wind speeds, and less air traffic. The aerial cameras take images from a high angle, allowing them to capture large areas in a single shot and allowing for accurate marking of suspect roof moisture contamination on CAD drawings. IR images show just the heat signatures of the roof—a roofing consultant must still interpret the data and give the final verdict.