The article below was written by Aaron Miller owner of Texas Inspector in the Dallas Ft. Worth area and is reprinted here with his consent.

Many of you have heard of infrared (IR) cameras and the supposed unbelievable feats they can perform, but most have not taken the time to uncover the real truth about them. In 2010 a Canadian television celebrity, d.b.a. Mike Holmes, declared himself to be the leading authority of the home inspection industry in North America and beyond. Due to his popularity he launched a television series promoting this fallacy and his new Canadian home inspection company. In an effort to make himself stand out in the crowd of real home inspectors he chose to promote infrared cameras as a major, if not the only important, home inspection tool. Along with support consisting of pseudo-scientific hype derived from movies and forensic science television programs that focus on entertainment with little concern for facts, he proceeded to promote something different to the viewing public. Overall, it proved to be an extremely effective and profitable business strategy, which, in this case, resulted in a successful TV series for him. This, in turn, created a dramatic increase in sales for the manufacturers of infrared imagery equipment.  Like him or not, Holmes is a showboat of a salesman. Yes, Mike, his sponsors and the infrared camera industry in general profited greatly from this media circus. And, all at the expense of the home-buying viewing audience and the real home inspectors who protect them.

Infrared cameras are diagnostic tools that have many applications, most of which have nothing to do with inspecting houses. They also have many limitations. They cannot see inside of or through walls, or anything else. They can’t see water. They can’t see mold. They can’t see termites. In fact, all they can see is the infrared energy or temperature of a surface. In order for infrared cameras to provide any useful information they require a very controlled set of conditions and operating environment, which are almost never available during the course of a home inspection.

Inexperienced and unscrupulous inspectors attempt to convince prospective clients that merely owning an infrared camera makes one a superior inspector. The fact is that a pricey camera does not make up for lack of education, training, certification, and experience. Owning a copy of Black’s Law Dictionary does not make one an attorney. Owning a stethoscope does not make you a doctor.

Ever since Mike Holmes’ broadcasted his first ‘Holmes Inspection’ program, home inspectors across North America have been lining up to buy the cheapest infrared cameras on the market so that they can tout infrared services as part of their inspection process. They have even given the use of the cameras a high-tech name – thermography, and the operators are called thermographers. Sounds impressive, huh? To return to the earlier analogy, owning a copy of Black’s Law Dictionary does not make one a lexicographer.

A home inspection consists of what is primarily a visual inspection and is best performed by an individual who possesses a broad base of knowledge of all the systems and components in a home through hands-on experience as a home builder and certification as a residential inspector through the code-authoring agency, the International Code Council. The inspection is visual in nature, since inspectors are not typically authorized to perform destructive forensic investigations of builders’ or sellers’ homes. Most inspector standards of practice which are promulgated by state licensing agencies and professional inspector organizations specify that visual inspections take place without the use of "special tools". 

The types of tools that are most often useful to inspectors and usually considered to be the most important are ladders, flashlights, electrical meters and testers, screwdrivers, moisture meters, binoculars, etc. While their usefulness is extremely limited in almost all types of home inspections, infrared cameras can be helpful on certain occasions if the cameras are of the best quality, the atmospheric and lighting conditions are just right, and the camera operator is highly trained in its use. Therein lies the rub.

The cameras that most inspectors buy are at the bottom end of the technology and comparatively cheap (<$5K). They have very low resolution (about like a June bug’s vision) and an extremely narrow scope of field with limited accuracy. The idea that a home inspector can use these to scan an entire house is preposterous. The technology does present an opportunity for a home owner or home buyer to evaluate a dwelling from the standpoint of thermal bridges (missing or poorly detailed insulation), air leakage (poorly detailed air barrier), and even some moisture issues (rain leaks, plumbing leaks, & condensation in the walls). However a significant and accurate result can only be accomplished by using professional equipment (in the $25K+ range), utilizing an inspector who has the required training to operate the camera (in the $5k + range), understands the building science that indicates where and how to look, and has the overall experience and field training to interpret what the camera is indicating. In other words, you can buy a high-tech camera, but the system works only if the camera is pointed in the right place. Even then, the pictures are not self-explanatory. They need to be interpreted, and the human risk of interpretation is often a bigger obstacle than the technical task of picture taking.

Furthermore, in order to stay current with their skills, an infrared inspector has to use the technology at least weekly (preferably daily) and must continually update the required education and equipment over time. We are now into a minimum of a $30K investment just to get into the game. And then one would need to quit the home inspection profession in order to become a full-time thermographer. You cannot do both.

In order to perform quality Infrared inspections you must have the right equipment and right training behind you, and then you must perform the inspection under controlled conditions at the right time of the day. This usually means at night, when home inspections do not take place.

The infrared camera services that most home inspectors are advertising are really just a marketing gimmick, as opposed to providing the client any real level of additional security against liability. The services usually represent negligence at best (providing a service they are not trained to perform) and sometimes even fraud at the worst.

While Texas Inspector owns and uses an infrared camera from time to time when it proves to be practicable, he strongly urges anyone desiring a whole-house scan to hire a full-time professional, licensed HERS energy rating contractor. Do not fall victim to those that claim to provide infrared or IR inspections as part of their home inspection services. Look for these red flags that an inspection company does not have the proper training to perform an IR Inspection:

• They advertise that they will be providing IR services during a relatively brief 3 hour or less home inspection.
• They advise that they will be performing the IR portion of the inspection during daylight hours (After sunrise or before sunset is required for accurate readings).
• They advise that they will be performing the IR scans when the temperature differential between the exterior and interior of the building is not and cannot be made to be >20° F.
• They advise that it will be easy to identify water related issues on the interior or exterior of the home. (This is just so much BS).
• They advise that they can ascertain leaks in stucco exteriors. (Not true).
• They advise they will only do an interior or exterior scan of the home (not both as is required for accurate interpretation).

Most professional thermographers will take any scans of the exterior of the home prior to sun-up or after sunset. The whole purpose of using an IR camera is to look for temperature differences (indicated by the infrared light that radiates from an object) between various building components and trying to determine if they make sense. Once the sun is out, much of the ‘evidence’ is obliterated as the surfaces heat up under the rays of the sun. This will also very quickly affect the readings on the inside face of exterior walls and so even interior scans are often done before the sun has reached the particular wall(s) of concern.

Even a seasoned professional infrared inspector, with top of the line equipment, will advise that finding moisture issues is one of the hardest tasks to perform with an infrared camera. In order to perform this task properly, the technician usually has to artificially cause a significant temperature change to the structure of concern (often also accompanied by artificially lowering the air’s humidity in the region). This investigation takes a very thorough knowledge of building science (something the vast majority of home inspectors simply do not have) and much preparation. Even with all of this, useful results are not guaranteed.

A skilled thermographer will scan both the interior and exterior of a dwelling to allow a comparison between the two surfaces and seek to develop a hypothesis of what is occurring within the building structure at that particular location. Do you suppose that a home inspector would ever inspect just the exterior or interior of a home and advise that a given building envelope was OK based on only seeing only half of it?

To recap, an infrared camera is not a magic wand. It can also not impart to its operator magical skills or powers. It can be just another useful tool in the toolbox of a professional inspector. It should never be a reason to hire a home inspector.