A nuclear roof moisture survey is the only effective method for locating areas of wet insulation within a ballasted roof system or multi-layered roof assembly.

A nuclear gauge is used to detect varying levels of hydrogen ions within the roof system, with hydrogen being most abundant in wet materials.  Readings are taken in conjunction with physical sampling to determine a baseline reading for dry materials.  Typically readings are taken on a 10’x10’ grid pattern and transferred to a scaled roof plan showing a visual representation of the wet areas.  Readings over the dry baseline benchmark indicate damp to wet materials, with moisture content increasing with higher readings.