Resources
Understand before you act.
A building problem is not always where it becomes visible. A thermal signature does not necessarily indicate its cause. And the choice of a test or method often depends on the conditions present at the time of the investigation.
This section brings together answers, methods and references to help you better understand the phenomena observed, the tools used and the various diagnostic approaches.
Frequently asked questions
Answers to the questions you have about your building.
Water infiltration, moisture, thermography, roofing, concrete slabs, insurance: find quick answers to the most common questions before planning an assessment.
Can thermography detect moisture?
A thermal camera does not directly detect water. It measures surface temperatures. Under certain conditions, the presence of moisture can alter the thermal behaviour of a material and produce a signature that warrants further investigation.
Can the exact source of a water infiltration be found?
Not always with a single observation. Where water becomes visible may be far from its point of entry. The investigation may require combining observations, moisture measurements, thermography, the history of the problem and targeted testing.
Why do weather conditions matter in thermography?
Thermography relies on the analysis of temperature differences. Sunlight, wind, rain, indoor and outdoor temperatures, and heating or air conditioning can all influence the signatures observed.
Why measure slab moisture before installing a floor covering?
Excessive moisture can compromise certain adhesives, finishes and flooring systems. Testing documents the slab conditions before installation and allows them to be compared against the requirements applicable to the project.
My insurer requires a thermography report. What should I request?
You do not necessarily have to determine the type of assessment required yourself. Send us the request or requirements received from your insurer. We can review them to determine the scope of the mandate and the resources or qualifications needed.
Methods and technologies
The science behind the diagnosis
Rigorous methods. Data interpreted by trained professionals.
Behind every investigation are physical principles, test methods, observation conditions and, depending on the mandate, recognized standards.
Axiom combines instrumentation, protocols and human expertise to collect relevant data, put it in context and draw information useful to decision-making.
Technology measures. Expertise interprets.
Infrared thermography
Measuring radiation, interpreting temperatures.
An infrared camera does not see moisture, insulation or air infiltration. It measures infrared radiation from surfaces and translates it into apparent temperatures and thermograms.
Interpretation depends on surface temperature, material emissivity, reflected radiation, ambient conditions, distance, angle of observation and the characteristics of the measurement system.
Key concepts
Emissivity
The ability of a surface to emit infrared radiation. An inadequate estimate can influence the temperature measurement.
Reflected radiation
A surface can reflect some of the radiation from its surroundings. A thermal image must therefore be interpreted in context.
Delta T — temperature differential
Many building envelope investigations require thermal conditions that allow the phenomenon being sought to produce an observable signature.
Heat transfer
Conduction, convection and radiation influence the surface temperatures observed.
Thermal inertia
Materials absorb, store and release energy at different rates. This property is particularly useful in rooftop thermography.
Dew point
The temperature at which air reaches saturation under given conditions. This concept is essential in the analysis of condensation phenomena.
Building thermography can be supplemented by moisture measurements, temperature and relative humidity readings, pressurization or depressurization methods and other observations suited to the mandate.
The thermogram is a data point. The diagnosis results from its interpretation and correlation with other observations.
Technical reference: ISO 6781-1 — Thermal performance of buildings — Detection of heat, air and moisture irregularities in buildings by infrared methods.
Concrete slab moisture
Measuring moisture where it matters.
Slab moisture is not simply a reading taken at the surface. Its distribution varies through the thickness of the concrete and results must be interpreted according to the method used, site conditions and the requirements of the flooring system.
Standardized methods
ASTM F2170 — In-situ relative humidity
Standardized method for measuring relative humidity inside a concrete slab using probes installed in holes prepared at the prescribed depth. It provides quantitative data on internal slab conditions at the tested locations.
ASTM F1869 — Water vapour emission rate
Method using anhydrous calcium chloride to measure the water vapour emission rate from the surface of a concrete slab. It provides a result specific to the conditions present during the test period.
ASTM F2659 — Non-destructive electronic screening
Screening method using a non-destructive electronic moisture meter to compare moisture conditions in the upper portion of a slab. Useful for identifying variations and guiding the placement of additional quantitative tests.
This screening method should not be confused with a quantitative acceptance result when the project requires a method such as ASTM F2170 or F1869.
The choice of method and acceptance criteria must be established based on the intended flooring, manufacturer requirements, specifications and standards applicable to the project.
Water, infiltration and moisture
An investigation by hypothesis.
An infiltration is rarely diagnosed simply by observing where water appears. The point of entry may be far from the visible manifestation and the path may vary depending on rain, wind, construction and conditions present.
Investigation approach
1. Document the manifestation
Location, extent, history, frequency and conditions of appearance.
2. Observe the assembly
Understand how water could enter and travel through accessible components.
3. Measure
Moisture, temperatures, ambient conditions and other relevant data.
4. Formulate hypotheses
Identify plausible entry paths or mechanisms.
5. Test when relevant
For example, by controlled and progressive wetting of a defined area.
6. Correlate
Compare manifestations, measurements, images and test results.
7. Define scope
Determine what the data allows — and does not allow — to conclude.
The goal is not to confirm a hypothesis at all costs, but to test hypotheses against the data collected.
Building envelope, air and condensation
Understanding exchanges between the building and its environment.
The behaviour of the envelope depends on heat transfer, air movement, moisture and material characteristics. These phenomena can interact and produce similar symptoms.
Phenomena at play
Thermal transfer
Heat moves through assemblies by conduction, convection and radiation. Insulation discontinuities and thermal bridges can alter surface temperatures.
Moisture transport
Water vapour, condensation and liquid water are distinct phenomena. Identifying them correctly is essential to avoid automatically attributing any water presence to exterior infiltration.
Air movement
Pressure differences, wind, stack effect and mechanical systems can move air through the envelope and influence temperatures, comfort and condensation risk.
Dew point
Indoor temperature, relative humidity and surface temperatures are related to assess whether conditions may promote condensation.
Roofing
Exploiting the thermal behaviour of materials.
A dry area and an area containing moisture can absorb, store and release energy differently. Under appropriate conditions, this difference can create a thermal contrast that helps identify suspect areas.
The quality of the investigation depends on the type of membrane and insulation, solar radiation, wind, recent precipitation, cloud cover, observation time and roof geometry.
Thermography does not replace visual inspection of the membrane, drains, flashings, penetrations and other details. The methods are complementary.
Electrical and industrial thermography
Observing equipment under operating conditions.
A thermal anomaly is meaningful when compared to similar components, load conditions and the operating context. Acquisition must therefore be planned so that equipment can be observed under representative conditions.
Depending on the mandate, requirements may cover thermographer qualifications, identification of inspected and non-inspected equipment, visible and infrared images, load data, anomaly descriptions and suggested corrective measures.
Thermography documents thermal behaviour; it does not replace the electrical work, verifications or diagnostics that must be performed by qualified personnel.
Technical reference: NFPA 70B and insurance requirements
Drone inspection
An acquisition platform, multiple analysis methods.
A drone allows rapid documentation of elevated, hard-to-reach or large areas. Depending on the mandate, acquisition can combine visible imaging, thermography and photogrammetry techniques.
Acquisition capabilities
High-resolution visible imaging
Detailed documentation of rooftops, facades, envelopes and specific conditions.
Radiometric thermography
Acquisition of thermal images containing the data needed for apparent temperature analysis, when the system and conditions allow.
Orthomosaic
Geometrically corrected assembly of a set of images to create a continuous representation of a surface.
Photogrammetry and point cloud
Geometric reconstruction from images taken at different angles to document shapes, dimensions and positions.
3D modelling
Representation of the building or part of it enabling visualization, measurement and localization of observations.
Data quality depends on the flight plan, image overlap, distance, angle, resolution and weather conditions. In thermography, the radiometric principles applicable to ground-based acquisition remain relevant.
Building Condition Assessment
A structured evaluation of building condition.
The Building Condition Assessment (BCA) aims to collect and structure technical data on the main components of a building in order to evaluate their condition, identify deficiencies and better prioritize interventions.
The approach relies on an organized method rather than a simple general walkthrough of the building.
The five steps
Inventory
Identify the components, systems and information relevant to the building and the mandate.
Inspect
Document accessible and observable conditions and review available documents when they are part of the mandate.
Evaluate
Characterize the condition of components, observed deficiencies and issues that may require intervention or further analysis.
Prioritize
Put findings in perspective based on their importance, urgency and potential consequences.
Plan
Turn findings into actionable intervention priorities useful for management and capital planning.
Axiom BCA mandates are carried out with the participation of an engineering resource to support technical evaluation, component analysis and intervention prioritization.
Data correlation
An instrument provides data. The diagnosis comes from putting it in context.
A thermal signature is not automatically moisture. A high value does not necessarily identify its source. A visible anomaly does not always reveal the mechanism that produced it. Axiom therefore prioritizes the correlation of observations, measurements, conditions present, building history and, when relevant, test results.
Observe. Measure. Correlate. Understand.
The method depends on the question to be answered
You do not have to determine the test, instrument or standard required yourself. Describe what you want to understand, verify or document. We will determine the appropriate approach for the mandate.
Guides and resources
Prepare. Observe. Document better.
Some information gathered before our arrival can help guide the investigation and better understand how a problem has evolved.
Infiltration d’eau : quoi documenter avant une investigation?
Une infiltration peut se manifester loin de son point d’entrée. Plus l’historique est documenté, plus il devient possible de formuler des hypothèses cohérentes et de cibler les vérifications.
Condensation ou infiltration : comment reconnaître les premiers indices?
De l’eau sur une surface, une tache ou un matériau humide ne signifie pas automatiquement qu’il y a infiltration. La condensation peut produire des manifestations très semblables lorsque la température d’une surface descend suffisamment bas.
Comment préparer un bâtiment pour une inspection thermographique?
Une caméra thermique mesure les températures apparentes des surfaces. La qualité d’une investigation dépend autant des conditions présentes que de la caméra utilisée.
Votre assureur exige une expertise : comment préparer votre demande?
Une demande d’assurance peut concerner la thermographie électrique, l’enveloppe, une toiture, des équipements ou une autre vérification spécialisée. Le mot « thermographie » à lui seul ne définit pas suffisamment le mandat.
Dalle de béton : comment préparer les essais d’humidité avant la pose d’un revêtement?
Les systèmes de revêtement, adhésifs et finis peuvent être sensibles à l’humidité. Les essais doivent être planifiés en fonction du revêtement prévu, des exigences du fabricant, du devis et de la méthode ASTM applicable.
Thermographie électrique : comment préparer votre bâtiment ou vos installations?
La thermographie électrique compare le comportement thermique de composantes en fonctionnement. La préparation du site est essentielle pour obtenir des données interprétables et respecter les exigences de sécurité.
Inspection par drone : comment préparer le mandat?
Le drone est une plateforme d’acquisition. Le choix des capteurs, du plan de vol et des livrables dépend de l’objectif : inspection visuelle, thermographie, photogrammétrie, orthomosaïque, modèle 3D ou documentation d’une condition particulière.
Bilan de santé des immeubles : comment préparer un BSI?
Un BSI est une démarche structurée visant à dresser un portrait de l’état des principales composantes, à identifier les déficiences et à soutenir la priorisation des interventions.
Standards and references
Methods governed by mandate requirements.
Some mandates require the application of standardized methods, adherence to specific protocols or particular qualifications. Depending on the type of assessment, Axiom takes into account the standards, test methods, professional requirements and client criteria applicable to the mandate.
ASTM and concrete slab moisture testing
Test methods and conditions of use applicable to moisture assessment before floor covering installation.
Building thermography
Observation conditions, limits of infrared imaging and the importance of context in interpreting thermal signatures.
Electrical thermography
Principles, inspection conditions, qualifications and requirements that may apply to assessments of electrical installations.
Building envelope
Technical references concerning water, air, moisture, insulation and the behaviour of assemblies.
Insurance requirements
Requirements can vary considerably from one insurer and mandate to another. They must be verified before determining the scope of the assessment.
Your situation
A question about your situation?
Resources explain the principles. The diagnosis depends on the building.
Two similar manifestations can have different causes. The building's conditions, assembly, history and the environment at the time of the investigation must be taken into account. If you are observing a problem or need to meet a specific requirement, describe your situation to us.
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