Stressed thermography: what it can show (and what it can’t)

Thermography is most useful when it helps you make decisions:

• where to open up (if needed)
• where to air seal
• which transition details warrant checking

A thermal image records surface-temperature patterns. It becomes evidence only when the operator also considers indoor and outdoor conditions, pressure, materials, solar exposure, equipment, access, and the location of the complaint.

What it can do well

• show patterns consistent with leakage and other anomalies
• support targeted correction work
• reduce “guess-and-seal” approaches

What it can’t do

• see through finished assemblies
• certify that insulation is perfect everywhere
• replace proper access-based verification where required

Best results come from

• good temperature differential (when available)
• pressure assistance (where appropriate)
• clear objectives at intake

Start with a specific question

“Why is this room uncomfortable?” or “Which transition should be checked before repair?” is more useful than a request to scan the whole building. Share when the issue occurs, where it is felt, recent work, previous reports, and any areas that cannot be accessed or disturbed.

Read patterns with context

A visible anomaly can have more than one explanation. Pressure-assisted observations may strengthen or weaken an air-leakage hypothesis, but they do not turn concealed construction into a confirmed fact. Findings should distinguish what was observed, what may explain it, and what evidence would resolve the uncertainty.

A useful deliverable

• identifies the conditions and inspection boundary
• ties images to rooms, assemblies, or transitions
• separates observed patterns from interpretations
• records access and method limits
• prioritizes targeted correction or further verification

Choosing the next step

Some findings can guide a focused air-sealing task. Others need access-based review, airtightness testing, design input, or observation under different conditions. The report should make that distinction clear rather than imply that every anomaly has the same confidence.

Thermography does not certify hidden insulation, guarantee that every issue will appear, or replace required design, code, or destructive investigation work. Use it where better location evidence can materially narrow the next action.