This evidence-quality guide strengthens documentation; it does not convert observations into a diagnosis. Keep source, transport route, affected material and visible symptom as separate claims. The goal is an auditable record that another person can understand, repeat and challenge.
Build the evidence frame
State the question before collecting more data. Keep source, transport route, affected layer and visible symptom as separate claims. Define what result would support, weaken or leave each explanation unresolved.
Quality checks
- Use exact timestamps and fixed locations.
- Preserve original photographs and readings.
- Record weather, occupancy and equipment state.
- Document absent symptoms and control areas.
One clean comparison is stronger than many uncontrolled observations. Note simultaneous changes that could confound the result.
Confidence language
Use low confidence for isolated or poorly controlled evidence, useful signal for a repeatable association, repeat under controlled conditions for unresolved confounders, and strong enough for professional review when the record is reproducible and limitations are explicit.
Boundary and professional review
Stop ordinary observation when there is electrical or combustion danger, sewage, unstable materials, unsafe access, rapidly spreading water, suspected hazardous material or acute occupant symptoms. Professional review should receive the chronology, raw evidence, methods, limitations, competing hypotheses and the decision the evidence is expected to support.
Primary references for this topic family
These references ground the general building-science or safety context. They do not diagnose a specific house, replace local requirements or certify a repair.
