Internal insulation of external walls has a special influence on the physical behaviour of the construction. In particular, the diffusion of water vapour from the inside to the outside as well as a possible moisture ingress and the drying potential after driving rain, which is limited by internal insulation, must be taken into account when selecting the right insulation material with appropriate dimensions.
Limited moving components such as half-timbered surfaces or wall formers with inhomogeneous cross-sections require particularly good-natured interior insulation systems due to the material-related differences in building physics. In principle, there is a risk of over-insulation of timber-framed surfaces and the resulting impediment to the drying out of the entire building component. Special recommendations can also be found in the WTA data sheet E 8 5 00 D.