Scenarios of the future climate in Scandinavia point to a more humid climate, which will give traditional, well-tried constructions new challenges. Ventilated cathedral ceilings are exposed to the changing weather conditions on the site, and it is important to secure the long-term moisture durability of the construction.

Measurements in the airway in two ventilated cathedral ceilings with different roof covering materials were performed during the spring of 2009. The results show a difference in the thermal and moisture performance of the construction. Calculations of the mold growth potential have shown that a roof with black asphalt shingles has a greater risk of being attacked by mold growth than a roof covered with ventilated hot-dip galvanized steel (painted black).