A technical investigation is defined as:

"a process, carried out by a professional, for a specific purpose, aimed at validating and analyzing information in order to establish facts, draw conclusions, determining caus(s) and the making of recommendations, all with a maximum of certainty."
When building envelope defects have been noted, a technical investigation is often required in order to determine the cause and to propose corrective measures. Non-destructive and destructive investigations are usually jointly conducted.


Visual Survey
Recording on a plan, various anomalies with regards to building envelope components, including levels of severity.
Pressure Differential Survey
Diagram of the pressure differential gradient of the building to determine the potential air exchange induced by the stack effect or operation of mechanical systems.
In-Situ Monitoring
Installation of data loggers at suitable locations, savings, at time intervals as short as one minute, readings of temperatures, relative humidity or pressure which are then analyzed to identify the causual link associated with the risk of condensation. This is an effective diagnostic method when interior condensation problems are present, such as in a building housing an indoor pool or cold storage.
Thermographic Scan (Qualitative)
Infrared thermography, when applied to the building envelope, and combined with other validation methods, can qualitatively assess the overall performance of the thermal envelope. Heat loss due to conduction, convection, air exchange, radiation and moisture in the materials is visible using an infrared camera transfering different thermal images.
Blower Door Test (Quantitative)
Allows to quantify the performance of air tightness of the building envelope using a blower door, for comparison with other building industry standards (such as Novoclimat and Energuide / R-2000).
For verification purposes, it is imperative to validate the non-destructive investigation results, using a destructive diagnostic method. This type of investigation involves damage to the assembly in order to target the exact cause and nature of the failure.


Exploratory Openings
Openings made from the inside or outside, through an assembly of materials in order to validate the composition, configuration and condition of the components.
Smoke Tests
The precise results of air leakage on construction site is often difficult, particularly with curtain wall systems. When it is not practical or possible to quantify air leakage, smoke testing is an excellent alternative, using a smoke generator under a pressure differential to determine any infiltration or exfiltration on the inside or outside of the envelope assembly.
Water Spot Tests
If water infiltration problems reoccur, areas of infiltration are pin-pointed and gradually watered using a calibrated nozzle.
Laboratory Tests
Coordination of laboratory testing regarding compliance of building envelope element and the interpretation of results.
Note: Our technical investigation methods have been developed in accordance with current standards. When no Canadian standard is available, we rely on standards, mainly from Noth America, having worldwide recognition.


In the case of new building, should the envelope show signs of failure, GCLT can provide expertise that will enable a Client to produce an expert's report in court. If required, we can also be called upon as an expert witness.