Nuclear Roof Moisture Surveys

When is a Nuclear Roof Moisture Survey appropriate?

Nuclear (radioscopic) Roof Moisture Surveys are a form of non-destructive testing used to detect and document moisture content within a roofing system. Performed regularly, Nuclear Surveys can help identify latent moisture within the roofing system. Nuclear Roof Moisture Surveys provide an effective test method for roofing systems where infrared thermography is contraindicated such as those covered with high-density ballast or pavers.

Our Nuclear Flat Roof Moisture Surveys are performed by Certified Nuclear Gauge Operators using a nuclear density gauge. The equipment uses low level radioisotopes to detect hydrogen atoms present within the roofing system and produce numerical readout directly proportional to the number of hydrogen atoms present.

Because water contains hydrogen, higher count values will be observed when moisture is present within the roofing system. High counts may also be obtained at any point where more hydrogen atoms are present such as changes in membrane thickness, insulation thickness or other variations in roofing system density.

Before the Survey begins, the roofing system is plotted on a grid at 7.5 foot intervals. Gauge readings are taken at each grid point directly on the roof surface and recorded on a scaled map of the roofing system.

Once all the gauge readings have been completed, invasive testing is used to correlate gauge readings to moisture content within the roofing system. If moisture presence is confirmed, the perimeter if the damaged area is then  outlined with spray paint on the roof surface.

Once the size and location of problem areas have been noted, they are photographically recorded.  These photographs, along with our description of problem areas are included in our written report.