WestCon Tribune

At the March meeting, Scott Wood with the Four Star Cleaning and Restoration Building Science Institute spoke on how to interpret thermography and its relationship to construction defects.

Contrary to some belief, thermography is not an x-ray camera. Thermography is the use of an infrared imaging and measurement camera to “see” and “measure” thermal energy emitted from an object.
Infrared thermography has been available since the 80s, but not until recently has it been used extensively for building investigations. Using slides, Mr. Wood compared the use of thermography with that of a moisture meter and using our standard visual references.

In construction defect investigation, a visual illustration of an envelope system or specific component failure that resulted in damage is just as important as knowing how and why the system component failed. Infrared thermography has proven itself as a successful tool in providing understandable illustrations of damage that not only assists in failure analysis, but can be readily understood by adjusters, attorneys, judges and jurors.

The application of thermal imaging can be utilized in many areas of investigation. One of the primary factors behind many cases or projects is the inability of a structure’s building envelope to prevent incursion of moisture and other outdoor elements. The building code indicates the construction of a building is to be “weather tight”. The so-called waterproofing or water shedding characteristics of a building’s envelope is vital for ensuring the likelihood for an environment that will not foster and support mold or other biological growth.

In both “barrier” and “water-managed” EIFS systems, moisture intrusion into the facade is most often the result of missing, insufficient or improper detailing. Similar to other facades, without the attention to detail these systems are prone to water entry and failure.

Infrared thermography has proven to be helpful in the assessment of moisture infiltration into EIFS and stucco clad structures. Being able to provide a physical illustration of the moisture migration path is much more conclusive than extrapolating moisture meter probe locations and more cost effective than large intrusive test cuts.

Stone veneer as well as brick, stucco, and siding are common cladding material. Infrared thermography provides a means of not only detecting or verifying moisture infiltration due to missing components of faulty construction, but also monitoring and racking moisture migration paths within the walls.

For plaza decks and balconies, thermal imaging cameras can be utilized to determine or verify potential leak locations and moisture migration paths without the large expense of removing overburden.

Thermography has been widely used in roof moisture and heat loss surveys in low-slope or commercial roofs for years. This method is still one of the most effective, non-intrusive testing methods for determining moisture problems and relevant heat loss in these systems.

For at-grade foundation clearance, thermography is a non-intrusive tool used to locate moisture problems that lead to interior finish damage and structural deterioration of the sheathing, sill plate and framing along with the identification of mold and biological growth inside wall cavities.
This process can also identify migration paths between the sheathing and facade materials for moisture infiltration into windows or between windows and adjacent facade materials.

Thermal imaging can accurately locate water damaged components or materials that require remediation. These images can also provide a far better understanding of the leak source than cam be discovered with the naked eye.

Thermography assists the construction forensic expert by providing a non-destructive method to substantiate the visual findings or other means of testing with an illustrative test to indicate what is happening behind or inside the building envelope components.