An Architect and an Engineer Reveal: How Effective is Infrared Thermography?

We've written about how infrared thermography works and what a condo or co-op board can expect from a thermographic professional. Now we ask: How effective is infrared thermography? The answer is that this depends heavily on proper use of the infrared camera and conducting the survey under the right conditions. 

An infrared roof survey conducted in the middle of a hot, sunny summer day, for example, typically produces images without appreciable thermal differences because all of the elements — roofing surface, water, brick walls — show the same high temperature. Only when the roof cools after hours of sun exposure will meaningful thermal differences be evident in an infrared image. 

On A Clear Day I Can See Forever

Similarly, an infrared survey taken on a cloudy day produces inconclusive thermal patterns in the infrared images. The cloud cover prevents the roof from heating up during the day, which reduces radiational cooling at night, minimizing significant temperature differences. Roofing surfaces must also be dry during an infrared survey because in thermal images the moisture underneath the membrane is indistinguishable from wet areas on top.

While infrared thermography is an invaluable tool for investigating leaks and diagnosing other building problems, it is most effective when used in conjunction with a visual evaluation. Colors that indicate the presence of water in the infrared images must be confirmed by hands-on examination and possibly by using a moisture meter and/or opening investigative probes. Some spots that appear as warmer or cooler (depending on where in the building the images were taken) may not be water; they could be cooler areas caused by drafts or missing insulation, for example. But even in those cases, the infrared survey helps pinpoint heat and energy losses that should be addressed.

For best results, the person conducting an infrared survey should be a Certified Infrared Thermographer with professional training from a recognized infrared thermography organization that meets the standards of the American Society of Nondestructive Testing. Certification also requires classroom and web-based education and hands-on field experience.

Talkin' 'bout Interpretation

Properly evaluating a building's conditions, however, requires more than just taking infrared photos, even by a certified thermographer. The images must be properly interpreted with an understanding of what conditions cause water penetration and heating/cooling loss in a building, and how they can be effectively addressed with a comprehensive repair program.

The thermographer must have a thorough knowledge of building systems based upon training as an engineer, architect, or other building professional. Expect to pay anywhere from $3,000 to $6,000 for an infrared study, depending on the project scope.

Used properly by trained professionals, infrared thermography can certainly help you see your building in a new light.

Stephen Varone, AIA, and Peter Varsalona, PE, are principals at Rand Engineering & Architecture.

Photo licensed under Creative Commons Attribution-Share Alike 3.0 Unported

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