The premature failure of a costly insulated built-up roofing system is a major concern to every facility manager, military or civilian. Because of the interrelated and critical relationship existing between the various components of the roofing system, it is essential that these roofs be inspected twice a year and repaired, as necessary. The bi-yearly inspection not only requires a comprehensive evaluation of the surface area, but an in-depth look into the interior of the system to determine if moisture has penetrated the system and has begun to deteriorate the layer of insulation. Infrared (IR) thermography has proven to be a very successful nondestructive method of detecting moisture in the layer of concealed insulation.
The US Army Facilities Engineering Support Agency (FESA), located at Fort Belvoir, Virginia, has the responsibility for providing technical engineering assistance for the operation, maintenance, and repair of Army facilities throughout the country. As a troubleshooter for solving built-up roofing problems, FESA uses a roofing evaluation concept that incorporates a detailed visual inspection with a nighttime IR scan. Within the last two years, the two FESA teams have surveyed more than 281 buildings at 30 Army installations. Incredible as it may seem, wet insulation was detected during the IR scan in more than 31 percent of the roofs surveyed. This paper describes the visual and infrared concepts and techniques used during the FESA surveys.