Roof Moisture Survey

Infrared moisture surveys are conducted after sundown. Wet insulation absorbs more solar energy during the day and releases it more slowly at night than dry insulation — the thermal difference between wet and dry sections is measurable by an infrared camera for two to four hours after sunset, provided the day was sufficiently sunny to charge the roof surface. In Columbus, the optimal infrared survey window runs from April through October, when daytime solar intensity is sufficient and nights are cool enough to create the thermal contrast the camera measures.

The infrared camera produces a thermal image of the entire roof surface. Wet sections appear warmer than dry sections in the image. The surveyor walks the roof with the camera, capturing overlapping thermal images that are assembled into a composite heat map of the entire roof area. The heat map is then overlaid on the roof zone diagram, producing a documented moisture distribution map that shows which sections of the assembly are wet and which are dry.

Roof Moisture Survey decision points

What gets verified on the roof

Roof Moisture Survey questions

What is the best time of year to conduct an infrared moisture survey on a Columbus commercial roof?

April through October in Columbus provides the best infrared survey conditions — sufficient solar intensity to charge the roof surface during the day and cool nights to create the thermal contrast the camera reads after sundown. The survey window is typically 2 to 4 hours after sunset, starting when ambient temperature has dropped far enough for the wet/dry differential to be legible. Columbus's winter months are too variable for reliable infrared surveys; nuclear moisture testing is the appropriate method from November through March.

How accurate are infrared moisture surveys?

Infrared surveys accurately identify the general location and relative extent of wet insulation when conducted under appropriate conditions. They are not a precise moisture content measurement — a confirmed wet area should be validated with a core sample before the scope is written. Our protocol is to identify all thermal anomalies in the infrared scan, cross-reference against building features that could produce false positives, and validate remaining candidates with cores. We report the validation results alongside the thermal map.

Does a moisture survey require us to vacate the Columbus building?

No. The survey is conducted on the roof surface after normal business hours (for infrared) or during standard hours (for nuclear testing). No interior access is required for either method. For occupied buildings in the Downtown, Arena District, or Short North corridors where roof access is constrained, we coordinate with building management on access logistics before scheduling the survey.