Along with the increasing demands of energy efficient buildings, there are many different opinions about energy retrofitting of the exterior wall, with internal insulation. Several recognized building authorities, advise against the internal insulation that in many cases will promote a depleting process in the materials of the exterior wall. Previous research has shown a familiar dilemma, that the internal insulation will occur a moisture problem in several places of the exterior wall, when setting up a traditional interior insulation wall with wood, mineral wool, vapor barrier and plasterboard.
This report covers the hygrothermal studies of a solid brick wall with interior insulating without a vapor barrier, where new materials are used. Shown in this paper, with theoretical hygrothermal simulations, that a moisture problem will occur several places in the outer wall. These moisture problems will increase the risk of mold growing between the existing wall and the new insulation, and increase the moisture content of the beam ends with the risk of rot. When the masonry wall gets colder the risk of frost damages in the surface of the façade increases. The outer brick gets more freeze/thaw cycles during the heating season, which can affect the water content of the brick.
The orientation of the façade appears to have a great influence on the increasing moisture content in Danish outdoor climate. Especially the driving rain on the south orientated façade is of great importance to the massive moisture accumulation in the exterior wall, when insulating on the interior surface.