Roof Moisture Survey
The purpose of a roof moisture survey is to identify and locate wet insulation. Wet insulation may facilitate corrosion of steel roof decking and deterioration of insulation materials. The moisture also greatly reduces the thermal resistance or R-value of the insulation materials. When some common insulation materials like wood fiber board and perlite get wet, they lose their capacity to resist wind uplift forces.
Roof moisture surveys are required before existing roof systems are "re-covered" with a new roof membrane system. The purpose is to find and replace all wet insulation before the new membrane is applied.
In addition, roof moisture surveys can be performed as a quality assurance measure for new roof constuction. Owners want to verify that there are no open roof membrane penetrations and that none of the insulation got wet during construction.