Technical analysis
Weather-resistive barriers, drainage cavities and air-control layers for timber and lightweight wall systems.
Engineering scope
- Principle
- Wall durability depends on drainage at the exterior and control of air-transported moisture at the interior.
- Verification
- Windows, base flashings, corners and services must connect to the field membrane in shingle fashion.
- Field control
- Adjust vapour resistance and cavity design to local climate, indoor humidity and cladding system.
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.