Moisture surveys can determine if, where, and to what extent moisture has compromised a roofing system. By making this determination, a building owner may have more options regarding corrective actions. A moisture survey can save an owner significant costs by allowing him to replace only the damaged areas of roofing rather than the entire system.
Flood Testing: We do not recommend flood testing of roofs. Flood testing takes from 24 to 48 hours, is often inconclusive and can cause structural damage. As a result, NRCA and CRCA do not recommend conducting flood tests as part of a routine quality-control or quality-assurance program for new roof systems
Infrared Moisture Surveys: IR scans are the most common moisture detection method for identifying wet insulation on commercial roofing systems. During the day, wet insulation will absorb much more heat energy than dry insulation. At night, this heat is retained in the wet insulation longer and is released slower into the atmosphere. Most IR scans are done at night in order to capture this thermal signature of wet insulation trapped in a roofing system.
Nuclear scans: are slightly more expensive than infrared, but unlike an infrared scan, can be performed during the day. Nuclear testing can read through multiple layers of insulation as far down as 8” utilizing a radioactive isotope to emit high speed neutrons aimed at the roof from the roof surface. Nuclear scans use a nuclear gauge to detect various levels of hydrogen ions trapped within the roof system. The readings displayed by the gauge are a measurement of the quantity of hydrogen ions that are present within a detectable area beneath the gauge. Since hydrogen ions are present in water, these readings can be correlated to moisture content once a base line reading for a dry area has been established. This is more precise that the infrared scan.