Infrared: hot technology for diagnosing building ills: infrared cameras are becoming more popular as a non-invasive, cost-effective way to pinpoint moisture leaks, faulty wiring, construction defects and termite infestation.

Infrared (IR) inspection is a powerful and non-invasive means of monitoring and diagnosing the condition of buildings. An IR camera can identify problems early, allowing them to be documented and corrected before becoming more serious and more costly to repair. IR gives apartment managers and maintenance staff a new tool that can save time and money by detecting a host of problems, including moisture intrusion, faulty wiring, construction defects and termite infestation.

How Infrared Thermography Works

Thermography enables individuals to see and measure heat. All materials emit heat energy in the infrared portion of the light spectrum. The unaided human eye cannot see infrared light, but with an IR camera the user can see thermally, revealing temperature anomalies that can identify potential problems in buildings and their component electrical, mechanical, plumbing and waterproofing systems. Today's lightweight and rugged infrared cameras can see in real-time, record infrared images and measure the temperatures of target objects to within one-quarter of a degree Fahrenheit. Points of possible concern show up clearly as hot or cold in relation to their surroundings. Recorded thermal images can be inserted easily into reports and serve as valuable evidentiary data in cases involving controversy.

How IR Is Used

Infrared can be used in apartments and multifamily buildings to detect a variety of problems.

Moisture intrusion and potential mold in walls and ceilings. IR thermal imaging can trace the source and scope of water damage, and thus the potential for mold to develop in buildings, more accurately and reliably than other moisture detection technologies. Once an IR camera identifies areas with thermal differences, a moisture meter can be used to confirm that they represent moisture. (A moisture meter is a bar-of-soap sized, hand-held device that is run on the surface where moisture is in question.)

Leaking roofs. Roof leaks can cause costly damage to a building's contents and discomfort to its inhabitants. An infrared inspection can quickly identify missing or moisture-soaked insulation under a flat membrane. This enables the surgical repair of failed areas rather than the much more costly replacement of the entire roof. (See the sidebar above.)

Faulty electrical, mechanical and HVAC systems and components. Infrared cameras are effective at detecting overloaded circuits, faulty wiring and loose electrical connections, which generate heat and can pose fire hazards. 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, another source of energy waste.

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 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.

Missing or damaged insulation. An IR camera can quickly and nondestructively 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. Any 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 or uninsulated pipes, another source of heat loss.

Termites. Although considered cold-blooded creatures, termites generate heat when digesting cellulose, the main ingredient of the wood they consume. When large numbers of termites congregate in nests, a substantial amount of heat is concentrated in one area. As this heat moves through the walls or floors of a building, an IR camera can detect it on the surface.

Other. In addition to these problem areas, infrared can be used to perform energy audits and surveys, indoor air quality investigations and plumbing and radiant floor heating inspections.

Case Study: Detecting Moisture

"My IR camera, a ThermaCAM B2, really expedites the inspection process," said Richard Greet, Senior Consultant at SporeTech Mold Investigations LLC, Louisville, Ky. "And it has added credibility to who we are and what we are doing. As a result, our client base has broadened and our business is increasing."

Greer said that the IR camera detects problems faster than a moisture meter, which he still uses, but only to confirm suspect temperature color variations that the camera sees.

"These temperature variations tell me where there is moisture from hidden plumbing leaks, for example, that can't be seen with the naked eye," Greer said. "And they identify air infiltrations that can cause condensation and promote unwanted mold growth. Using the infrared camera virtually eliminates the need to tear down walls to pinpoint problems."

Infrared building contractors generally charge an hourly rate, depending on their experience and market conditions. Some contractors charge a lump-sum fee for the community; others charge per unit or based on square footage.

Greer used an IR camera to locate serious exterior cold air leaks in one apartment at Station House Square, a 94-unit apartment community in Louisville, within five minutes. "The cold spots prompted condensation and consequential mold growth due to a 79 percent humidity level caused by a faulty dryer vent. Problems found, problems fixed, no more problems," Greer said.

Jennifer Montgomery, Station House Square's Manager, said, "Not having to tear down walls to find the problem is a big advantage from our point of view. That's definitely something we don't want to do if we can avoid it."

Travis Holland, the community's Maintenance Manager, also found the technology impressive. "Richard came back to us with a report that included a printout of the image showing the location of the moisture," Holland said. "Once we make the necessary repairs, we'll rescan the area to show that the moisture is gone. That will give us documentation that we've corrected the problem in case any mold-related legal issues come up."

Operating the IR Camera

Regardless of what an IR camera is used to look for or at, its effectiveness is dependent on the contractor's knowledge and understanding of the component being inspected, and on his or her skill in operating the camera and understanding the science involved in assessing the thermal evidence it presents.

To meet the demand of the building diagnostics market, the Infrared Training Center (ITC), which is the world's largest thermographer training organization, in conjunction with the Building Science Institute (BSI), has created a curriculum in Building Science. ITC's three-and-a-half-day Building Science Certification class is the only training course in the United States that's ISO-9001 registered. Upon successful completion of the class, students become Certified Building Science Thermographers, so if they work for an ISO-9000 company, they'll have fulfilled their obligation for proper training.

RELATED ARTICLE: IR for roof inspection.

BY DOUGLAS C. TAIT

Infrared thermography used in roof inspection is beneficial in reducing the number of hours spent on pinpointing areas that need repair; identifying leak areas before they become a major cause of property damage or mold; reducing total structure replacement; and assisting in nondestructive investigation.

Two types of IR inspection methods can be used for roofs: walk under/walk through and walk over.

A walk under inspection is used to inspect interior and exterior structures.

This method is quick, does not require roof access and may take place during the day.

In a walk-over inspection, a thermographer and an assistant walk on the roof with an IR camera and a moisture meter looking for spots showing thermal differences.

This type of inspection provides verifiable results, covers the entire roof and takes place at dusk, night or sunrise.

By performing the inspection at dusk, the roof temperature is cooling along with the air temperature, but moisture-laden insulation, wood and other substrates will retain heat that can be picked up with an IR camera.

Inspection Reports

Once a roof inspection is completed, there are a few options for action and reporting.

1. The areas of moisture can be marked with no written report or follow up.

2. A formal written report can be compiled with infrared and digital image comparisons and moisture can be confirmed with the use of a moisture meter.

3. An extensive report could also include ASTM C1153-97 Standard Practice for Location of Wet Insulation in Roofing Systems Using Infrared Imaging. This may involve a structural engineer and a licensed roofing contractor to repair core locations.

Ideal Conditions for IR Roof Inspection

* Clear sunny day

* Clear night, no cloud cover (for low sloped roofs)

* Little or no wind

* Dry surface that is clean and clear of dirt and debris

Poor Conditions for IR Roof Inspection

* Insulation with different R-values or different absorption characteristics

* Different internal building temperatures

* Large ballast or extra gravel left on the roof

* Warm or cold air exhausting onto the structure

* Internal sources of heat or cold, such as lights, heaters and steam pipes

* Water ponding or water spray

Douglas Tait is a representative for Miller Miller & Mac-Florida Inc. He has written articles and has chaired many state and national committees on building components and roofing systems. He is certified in Thermographic Infrared Inspections and Building Sciences, is a member of the Roof Consultants Institute and the Florida Roofing & Sheet Metal Association. He can be reached at 407/850-0697.

Dick Price is Business Development Manager, Thermography Division, for FLIR Systems Inc. He is responsible for FLIR's new market development and the building diagnostics market, including home inspection and water restoration. Price has been involved in advanced technology for more than 35 years. He holds degrees in business and computer sciences and is a Certified Thermographer