Infrared Technology for Home Inspectors

Infrared technology, is it cutting-edge technology, the tool of the future for home inspectors? Or will home inspectors decide to take a pass, viewing the technology as more trouble than it’s worth?

Many home inspectors are watching the development of the technology and weighing its relevance to their profession. When asked, the ASHI Technical Committee expressed the opinion that today, it’s more likely to cause problems than to provide solutions. On the other hand, Dick Price, a representative from infrared camera-maker FLIR and the company’s training center, explains how he believes inspectors can use the technology, as well as his company’s cameras.

Inspecting with infrared  

As business development manager for the Infrared Training Center, there’s nothing I enjoy more than sharing infrared technology success stories.

One of my favorites comes from Scott Wood, division manager for the Environmental Division of Four Star Cleaning and Restoration in Fremont, Calif. According to Wood, a leak appeared in the kitchen ceiling of a $3 million home in a gated community. The homeowner assumed the water was coming from an upstairs bathroom, directly over the kitchen. The 8x8x6-foot bathroom was completely paneled in marble. The cost to rip out the marble, identify the problem, make the necessary repairs and replace the marble was estimated at $80,000. But when the homeowner mentioned that the leak occurred after rainstorms, it was decided to use the FLIR Systems infrared camera. An inspection with the camera located an 8-foot wide path of wet materials leading to the threshold of a French door that opened to an upstairs porch. The water wasn’t coming from the bathroom after all. The clogged weep hole under the threshold was opened, and this quick, simple repair took care of the problem, saving the homeowner the major inconvenience of tearing up the bathroom and from wasting $80,000. See illustration.

I also like the success story about infrared being used in the entryway of a home to determine that the under-floor radiant line spacing was below the designer’s specified instructions. Infrared also can be used to view different radiant flooring heat zones, crimps in tubing and other post-installation validation concerns, often saving time and unnecessary destructive investigation. See illustration.

And in another home, an IR image immediately identified the source of energy loss—missing insulation on the roof and rafters. See illustration.

These success stories are possible because infrared (IR) thermography, also called thermal imaging, can instantly detect moisture in building materials as, typically, wet areas on interior building surfaces are cooler by several degrees Fahrenheit than materially similar, but dry, areas. As a result, an IR camera can be a useful tool in identifying moisture water intrusion. Because mold requires moisture to grow, the camera can be helpful in identifying likely areas of mold contamination.
But detecting moisture intrusion and possible mold is just one of the ways infrared technology is being used to diagnose the condition of building envelopes and components. There are some additional ways it’s being used.

Detecting missing or damaged insulation

An IR camera can quickly and non-destructively detect areas of missing, moisture-laden or otherwise damaged insulation in walls, crawlspaces and attics or around doors, windows, electrical outlets and other access plates. All of these problems can increase a building’s energy costs by allowing cold air to enter the building and heated air to escape in the winter and the reverse in the warmer, summer months. IR can also identify poorly insulated or uninsulated pipes, another source of costly heat loss.

Detecting faulty electrical-mechanical and HVAC systems and components

Infrared cameras are used to detect overloaded circuits, faulty wiring and loose electrical connections because they all generate heat. IR can detect thin spots in furnace heat exchangers and flues, mechanical problems such as worn, under-lubricated pumps, motors and bearings in fans, compressors and furnaces, electrical faults, refrigerant leaks and blockages in HVAC components.

Detecting leaking roofs

An infrared camera in the hands of a trained inspector can identify missing or moisture-soaked insulation under a flat roof membrane roof where the insulation needs replacement, permitting the surgical repair of failed areas rather than the more costly replacement of the entire roof.

Finding construction defects

The increased use of EIFS (Exterior Insulation and Finish Systems) and stone, stucco, brick veneers and siding as facades on residential, as well as commercial, buildings invites the possibility of water intrusion if they are not properly installed. IR can detect or verify moisture infiltration in these weatherproofing ‘barrier’ systems, usually the result of insufficient detailing such as inadequate or improperly applied flashing or sealants. In addition, IR can monitor and track moisture migration paths within the wall cavity.

Conducting post-fire inspections

After fires, IR can quickly locate remnant hot spots, assuring the fire is completely extinguished and provide invaluable data for insurance companies’ cause and origin investigations. The clear IR images of normally invisible diagnostic evidence can assist in the planning and execution of the restoration effort and in the settlement process.

Even termites

Although considered cold-blooded creatures, termites are hosts to bacteria, which help break down and digest cellulose, the main ingredient of the wood they digest. The digestion process generates heat, and when large numbers of termites in nests congregate, a substantial amount of heat is concentrated in one area. As this heat moves through the walls or floor of a building, an IR camera can detect it on the surface.

In addition, infrared is being used to perform energy audits and surveys, indoor air quality investigations, and plumbing and radiant floor heating inspections.

Limitations

IR covers so much more area and gets into many places not accessible to moisture meters, which require contact with the surface being inspected; it finds things that would never have been found with a moisture meter alone.

But there is still a role for moisture meters. Infrared, which can quickly locate the probable presence of moisture by identifying temperature variations as slight as +/- 0.25° F in building structures, can’t detect moisture per se or how much is present. For that, you still need a moisture meter to identify an abnormality you might see on an IR thermogram, and to confirm that the temperature differential you’re seeing is actually an indication of moisture and not something else, such as an insulation void or multiple layers of building material.

In addition, thermal imagers show all types of differences in temperatures. An air leak (infiltration) and water can look virtually the same in the infrared image. Moisture meters are the better instruments to make the final determination.

The combination of IR and moisture meters can mean little or no destructive testing is required, allowing for substantial
savings for the building owner, or homeowner or other responsible party.

The need for training

Regardless of what an IR camera is used to look for or at, its effectiveness is dependent on two factors:

• The inspector’s knowledge and understanding of the component being inspected,
• The inspector’s skill in operating the camera and his or her understanding of the science involved in the assessment of the thermal evidence.

The trained and experienced thermographer knows that every hot or cold spot does not represent a problem, but may, in fact, reflect a component’s normal operation, performance or location in the structure. Alternatively, a thermal image may actually show heat from sources other than the target that is reflected from or transmitted through the target material.

To meet the need for training, the Infrared Training Center (ITC), in conjunction with the Building Science Institute (BSI), created a curriculum in Building Science. The three-and-a-half-day Building Science Certification class is ISO-9001 registered.

How Infrared Thermography Works
Thermography enables us to see and measure heat. All materials on earth emit heat energy in the infrared portion of the spectrum. The unaided human eye cannot see in the infrared. Thermographic, or simply thermal, images, allow the user to see thermally, revealing anomalies that might be indicative of problems in buildings and their component electrical, mechanical, plumbing and waterproofing systems. Today’s lightweight and rugged infrared cameras see in real-time, record infrared images and measure the temperatures of target objects quite accurately—to within +/- 0.25° F. Points of possible concern show up clearly as hot or cold in relation to their surroundings. Recorded thermal images can be easily inserted into reports and distributed by e-mail, facilitating communications among trades, attorneys and other professionals, and serving as evidentiary data in cases involving controversy.

Photo:
New, high resolution FLIR ThermaCAM® B-Series infrared cameras are designed to detect moisture intrusion and other building defects and problems. The 1.5-pound B1 shown is a rugged, ultra-compact and affordable model available for less than $9,000 that can instantaneously inspect entire rooms — including places that are difficult to reach. All B-series cameras store thermal images as JPEG files that can be easily downloaded to a PC and used with Microsoft Office® and other software to generate reports literally with the click of a mouse. FLIR is unique among camera makers in that it rents, as well as sells, its cameras, with most of the rental fee applicable to subsequent purchase.