JÖrg Jude GebÄudetechnik
Internal Insulation Humid Walls
Internal insulation with calciumsilicate panels
About 90% of todays residential buildings have been build before 1977, the day when the law of the first heat insulation act came into effect. Excluding the area of the modernisation of windows these houses are predominantly in an energetically insufficient state. Exterior walls of typical old buildings have a U-value of about 1,4 W/m²K. With a 5 centimeter thick internal insulation U-values of 0,6 W/m²K are reachable without fearing excessive exposure of humidity within the construction. Where objects because of aesthetical reasons or because of reasons for the preservation of sites of historic interest cannot have an external insulation calciumsilicate panels allow the improvement of the heat insulation as an internal insulation. Calciumsilicate panels are principally plates of cellular concrete. For the most part they consist of lime, cement and sand as well as a binder. They are more foamed up and therefore still lighter than plates of cellular concrete. Calciumsilicate panels are a natural building material with very good properties. They can incorporate and emit humidity up to three times of their own weight without losing their shape. They are therefore suitable for the permanent removal of defrost water stress on the inner sides of outside walls and involved appearances like bad smell, the decay of the internal plaster, humid walls, detachments of surfaces as well as the development of mould accompanied by health problems. For basements which are supposed to be converted for living purposes an external insulation is always connected with costly spoil works. Altogether the internal insulation is financially less costly than the closed thermal shell for the exterior wall. Lasting construction damages like for example defective horizontal sealings or leaking facades have to be removed in each and every case.
