Moisture shows as brighter sections white in this case
An infrared roof survey is used in a flat roof inspection to locate moisture in a roof by seeking areas of increased surface temperatures. During the cold weather season, heat from the building interior is lost at a greater rate through wet roof areas and elevates the surface temperature. Alternatively, during the warm seasons, solar heat is absorbed into the wet area, and then retained for hours after the sun sets.
To understand the methodology for infrared roof evaluations, it is important to first comprehend how thermal differences are detected and analyzed when applied to areas of wet and dry insulation. Roof areas that contain moisture have higher thermal conductivity and capacitance than dry areas. During the day, the sun radiates energy onto the entire roof surface (solar loading). Later in the day, the wet insulation has the capability to retain more energy (heat capacity). Areas of the roof that are of higher mass (wet) retain heat longer than the lower mass (dry) areas and therefore radiate heat for a longer period of time, because it takes longer to cool.
When viewed through the infrared imager, wet areas appear as brighter, lighter tones of gray in black and white images. Alternatively, in color images, wet areas will appear as hotter colors. In general, the higher the concentration of water, the higher the surface temperatures.
Moisture shows as bright orange across the darker ballast roof
Because higher surface temperatures and consequently hotter colors may be produced by several phenomena not related to moisture intrusion, additional tests are made to verify the findings of the infrared inspection including core cuts and other non-destructive testing methods.
Please contact us for more information or to schedule your next flat-roof inspection.