If you have a commercial building with a large flat roof, you may wonder whether it has any moisture damage. It's often difficult to know for sure since the insulation boards and deck are covered up with roofing. In some cases, roofers may cut out small sections of your roof so they can test them for moisture.
However, you might prefer having a roof moisture survey done that doesn't require cutting. Here are two popular ways a moisture survey of your roof might be done.
Thermal imaging can tell what's going on underneath roofing because it measures temperatures and displays the temperatures as colors on video and pictures. Dry roofing has a different temperature from wet materials, so the colors are different. One of these roof moisture surveys can be done by hand when a roofer walks over the roof or it can be done from the air by a drone, plane, or helicopter.
The entire roof is examined, and you'll be provided with a video or pictures that show you where water damage is located so you can see it with your own eyes and know if your roof needs to be repaired. One reason to have a roof moisture survey is to learn if you can cover up your old roofing with new roofing or a coating, or if everything needs to come off and be replaced due to moisture issues.
Nuclear Roof Moisture Survey
A nuclear roof moisture survey is done with equipment that is rolled across your roof. It can even be done on roofs covered with rocks as long as the rocks are moved out of the way when the survey is taken. This survey method is done by walking across your roof in a grid pattern and taking readings every few feet. The roofer marks spots on the grid map to identify where nuclear readings found increased moisture.
The nuclear meters are contained, so there is no danger in using them. The readings are sometimes confirmed with core samples that identify the degree of water damage found by the test. When the roof moisture survey is done, you'll have an understanding of your roof moisture problem, and you'll know how to proceed with roof repairs or a replacement.
The goal of having a roof moisture survey done is to make sure you are aware of moisture problems so rotted areas of roofing don't get covered with new roofing and continue to rot. You might want a survey before you get a new roof or as part of a routine roof inspection.