SEASONAL MOISTURE CONTROL REFERENCE
Wuhan Tianhe Airport Roof: Seasonal Vapor and Drying Strategy
Large conditioned airport roofs require membrane selection that accounts for summer cooling, winter operation, air leakage and construction moisture that may reverse the drying direction.
SEASONAL MOISTURE MAP
Check both heating and cooling conditions before fixing vapor resistance
Winter outward drive
Warm interior air may move toward colder exterior layers. Control air leakage and evaluate where vapor resistance is needed before moisture reaches cold surfaces.
Summer inward drive
Hot humid exterior air and solar-heated roof layers can create an inward drive toward cooled interior zones. Avoid assuming a winter-only layer arrangement covers every condition.
Air leakage dominance
Gaps at curbs, facades and services can move moisture more rapidly than diffusion. Identify and inspect one continuous air-control plane.
PRODUCT & DELIVERY
Inputs required for moisture-consistent product selection
- Complete roof build-up, control-layer positions and expected drying direction
- Winter, summer and peak indoor/outdoor design conditions used for review
- Named water, vapor, air and mechanical test methods and required documents
- Roll dimensions, accessories, seam concept, exposure period and moisture acceptance plan
- Private-label artwork, product and batch labels, roof-zone and inspection identifiers
RELATED PRODUCTS
Use building physics before product ranking
FAQ
Seasonal airport roof moisture questions
Can the vapor drive reverse in an air-conditioned airport terminal?
Yes. Winter conditions may drive interior moisture outward, while hot humid summer conditions and cooled interior zones can create inward drive. The direction and magnitude depend on actual temperatures, humidity, solar effects, air pressure and layer resistances, so the project should review more than one design condition.
Does a very breathable exterior membrane guarantee outward drying?
No. Drying depends on every layer and the available air or drainage path. A vapor-open membrane cannot release moisture through another low-permeance layer, remove standing water or compensate for wet insulation and uncontrolled air leakage.