Vapour Diffusion

Cooperative investigations facilitate the control of damage to timbers by humidity

In the case of occupied dwellings, vapour diffusion is without problems, provided the temperature is similar on both sides of the supporting structure. However, the situation changes in dwellings below roofs that  are not insulated roof structures or located above building cellars. Verification pursuant to DIN 4108-4 is essential here. Furthermore, a three-dimensional representation of the interactions between the fabric constituents may be needed.

We have access to the technological services of the German  Institut für Bauklimatik of Dresden Technical University for this purpose. When installing internal insulation systems in buildings with older timber-beamed ceilings, the beam ends specifically act as heat transfer and diffusion bridges. Contrary to the former prevailing opinion that everything in a building needs to be rendered vapour-tight, it is now accepted that superstructures that are open to diffusion are a much better solution. Because of the large number of factors of influence, every building needs to be considered as a separate object.