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Thermal cameras in moisture inspection of building roofs

Once moisture has entered the building roof due to rain, snow, or condensation, it may travel wide and far, and it’s difficult to trace its source. If left in disrepair, concrete absorbs water, and wood rots, thus causing damage.

Compared to the traditional solution of breaking open the entire roof, a thermal camera is a better choice for detecting water in hard-to-see areas, such as underneath the roofing membrane (insulation) and above the ceiling.

Generally, moisture produces only subtle temperature differences that require a thermal camera with good resolution and thermal sensitivity. With a brilliant sensitivity of 40mK and a resolution up to 384x288, the FOTRIC 320 series thermal imagers can reveal substantial temperature details. Moisture issues appear most significant for a temperature spanning between 10° and 20°C, and FOTRIC cameras are highly qualified with a fantastic minimum span as low as 2°C.

For roofs under the sun, they cool after sunset, but the trapped water under the roof cools much more slowly because water has a higher specific heat capacity than solids, retaining heat longer. So areas with trapped water can be seen in a thermal image based on temperature differences. In contrast, for roofs without direct sunlight, the temperature of the roofing surface is close to the ambient temperature, and the water beneath the roof surface cools as it evaporates, displaying cooler than dry areas.


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