The core idea
Cold surfaces, stack effect and lower outdoor moisture can make winter symptoms differ sharply from summer behavior.
How the mechanism works
Heating changes temperature gradients, indoor pressure and relative humidity while exterior materials may freeze.
When it becomes relevant
Typical trigger: Sustained cold weather and heating operation.
Evidence that supports this interpretation
- Symptoms follow cold intensity
- Upper-level leakage or window condensation increases
- Patterns ease in mild weather
Evidence that weakens it
- Rain alone controls the symptom
- Cooling operation is the trigger
- No seasonal change exists
What this concept cannot prove alone
A single observation, image or meter reading cannot confirm the complete failure pathway. Use this concept to form better questions, compare alternatives and decide which safe observation would be most informative next.
Safety and professional boundary
Combustion and frost-related roof issues require appropriate professional assessment.
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.
