When a location like an attic space is covered with zinc on the roof and facade it is essential to determine if this attic is part of the building or not, in relation to building physics. Concerning vapour diffusion it is essential for the build-up to treat the attic as a part of the building, because there are demands on ventilation and build-up to prevent corrosion of the zinc.

In a cold roof construction there is always a good ventilation present under the zinc roof covering to ensure a good application. When a warm roof construction is selected the mayor concern is vapour transport through the construction. The architectural structure of the roof of this application must be completely (100%) vapour-proof.