Use this atlas page to organize evidence, not to declare a diagnosis. Grade, surface runoff, groundwater, drains and capillary pathways around below-grade construction. The useful starting point is a repeatable pattern tied to location, timing and conditions that changed or stayed normal.
Read the visible pattern
Start by matching the symptom to the operating state of ground & drainage. Record the first location, direction, edge or cycle where the symptom becomes noticeable. Photograph from the same position, preserve original timestamps and note comparable areas that remain dry, quiet, cool or odor-free.
Trace the connected mechanism
Water pressure and soil moisture can change by event, season and nearby drainage condition rather than remain constant. Compare at least two plausible routes rather than choosing the first familiar explanation. Ask what this system predicts about location, delay, direction, recurrence and unaffected comparison points. A strong hypothesis predicts where the symptom should begin, what trigger should reproduce it and which nearby areas should remain unaffected.
Use safe, non-destructive checks
- Observe where roof water discharges
- Map wetting after comparable rain
- Compare wall, slab and soil patterns
Pair every reading with its instrument, location, time and environmental condition. One reading can support a pattern but cannot certify a hidden material condition or prove that a repair is complete.
Respect the stop boundary
Excavation, unstable soil, contaminated water and active flooding require qualified planning.
Prepare the next decision
Summarize the trigger, first visible change, rooms or systems involved, checks already completed and what would count as a verified outcome. A useful handoff gives the next person a timeline and competing explanations instead of only a symptom label.
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.
