Technical analysis
Why the warm-side rule requires climate, operating condition and hygrothermal verification.
Engineering scope
- Principle
- The layer normally limits vapor and air entry into colder parts of an insulated assembly.
- Verification
- Seasonally reversed vapor drives, cold-storage buildings and high-humidity spaces may require a different strategy.
- Field control
- Confirm material vapor resistance, layer sequence and continuity by project-specific analysis.
System decision
Start with the actual roof or wall build-up, climate, indoor condition and risk at the relevant interface. Product data must be connected to a defined layer and detail.
Documentation and acceptance
Keep design details, approved product data, delivery labels, batch records, mock-ups, concealed-work photographs and repairs traceable to the installed area.