Thermography Inspection

How many times have your building inspectors wished they could “see through walls” to evaluate building or infrastructure fitness or troubleshoot problems? Although infrared thermography does not literally see through materials, it is invaluable as a nondestructive tool for facility and infrastructure maintenance. Even minor temperature differentials caused by the presence of water, for example, are easily evident in infrared imaging.

Thermography is the use of infrared energy to detect anomalies in building construction. Since heat is emitted by all objects above the temperature of absolute zero, (-273 degree Celsius) it is possible to detect a heat signal given off by all objects given the right circumstances. The greater the surface temperature emitted from the item equals the increase in infrared energy emitted. Thermographic imaging can detect up to 0.05 deg. Celsius differences on wall and ceiling surfaces. The thermographer must be able to properly interpret the infrared image from the camera. In the case of the heat transferring from the wall surface, various background transmissions usually are observed (insulation, wall studs, nails, dampness, electrical components, heating, structural items), and these need to be interpreted as well. In addition to background items the surface of some materials reflect heat and do not give a consistent heat emission. This is where proper training of the thermographer is required.

Training in thermography is a three step process, level three being the most involved. The Government of Canada National Master Specifications has issued the minimum qualifications for a qualified thermographer which is NMS 022713. Obtaining these credentials ensures the inspector has completed the minimum 32 hour training course with a grade of at least 70 percent. The equipment required should also meet or exceed the qualifications of the NMS Specifications.

Thermography can be used in any home inspection to detect the infiltration of air, missing of misplaced insulation, moisture/dampness/water, and overheating electrical connections. It is also used after flood damage clean up to ensure there are no hidden wet construction materials. In using the equipment there must be at least a 10 degree temperature difference between surface temperatures to get a proper reading. Therefore there are certain times in spring and fall when the outdoor temperature is too close to the house temperature for proper detection. It is also very useful for flat roof water detection.

Anyone purchasing or selling a home or business is a good candidate for a thermographic review. It will give the purchaser a more complete view of the building.

A complete list of Thermographic tools, educational courses and other thermographic information may be obtained by visiting the Snell Infrared Canadian Training Centre at www.thesnellgroup.com