Define the question before measuring
Brick veneer and cavity walls need clear drainage routes at the base and above openings.
Capture a useful baseline
Record the exact location, date, current weather or equipment state, recent activities and the first visible, audible, sensory or measurable change. Keep one unaffected reference point.
Safe observations to repeat
- Locate weeps and flashings visually
- Record rain orientation
- Compare affected and unaffected openings
Compare supporting and weakening evidence
Supports the pathway
- Symptoms appear above or below openings
- Weeps are absent or blocked
- Mortar droppings may bridge the cavity
Weakens the pathway
- The wall is solid masonry without a cavity
- A roof leak enters above
- The mark follows indoor humidity
Interpret the result conservatively
Look for a repeatable relationship between trigger, location, timing and change. Treat exceptions as useful evidence rather than forcing every event into one explanation.
Escalation boundary
Cavity opening and masonry repair should preserve structural ties and flashing continuity.
Close the loop
If work is performed, repeat the same observation under a comparable trigger and through the original lag window. Record both recurrence and non-recurrence events.
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.
