Define success before work begins
For Exhaust fans and depressurization, success must be tied to the original symptom and trigger—not merely to a clean or newly finished surface. Write the observable pass and fail conditions before the baseline is lost.
Recreate the relevant trigger
Use comparable weather, water use, equipment state, occupancy or temperature where safe. If the original trigger cannot yet occur, record that verification is pending rather than declaring resolution.
Respect the lag and recurrence window
Allow enough time for fans, stack effect, wind and duct imbalance move air through both intended and unintended routes to produce the original result. Some routes appear immediately; others require sustained operation, drying, rain direction, snowmelt or repeated cycles.
Failure signals and partial improvement
Record reduced intensity, delayed recurrence, movement to a new location or dependence on a narrower trigger. These are useful outcomes but may indicate partial control rather than full resolution.
Build the professional handoff
Share room-use conditions, fan states, door behavior, supply and return observations, temperature differences and any combustion appliances nearby. Include the baseline, controls tried, source references, remaining alternatives and any condition that could not be safely checked.
Close or reopen the pathway
Close the case only after comparable events remain stable through the agreed review period. Reopen it when the original pattern returns, a new connected symptom appears or the verification method was not comparable. The source set for this guide includes 4 official records selected for this path. They provide general technical and safety context; they do not determine the condition of a particular house.
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.
