Condensation risks in wooden building components are mainly caused by water vapor penetrating the cross section of the component through airflow. Even small pressure differentials result in a lot more vapor flowing through a joint of only a few millimeters than that which would migrate by diffusion through many more undisturbed square meters of area...

Based on an application for standardization by the company ISOVER in October 2007, the German Industrial Standard DIN 4108 – 11 has been cleared by the responsible bodies in DIN for review by the committee NA005-56-93AA, “Airtightness”. The work on the details of the standard has been going on for seven and a half years now...