HARTWIG M. KUNZEL Fraunhofer-Institute for Building Physics, Holzkirchen
Exterior thermal insulation composite systems (ETICS), in the US called exterior insulation finish systems (EIFS), provide heat insulation and moisture protection of building structures. They are increasingly applied to new and old buildings especially when moisture related problems, for example, corrosion or frost damage, have to be dealt with. In most cases a quick drying of the wall beneath the insulation system is expected. The drying out time of masonry after application of ETICS and the different influencing factors have been determined by field tests and experimentally validated calculations. The paper considers applications of ETICS on calcium silicate brick (standard case), on wet aerated concrete, AAC, (extreme case) and on exposed historical brick walls (rehabilitation case). ETICS with mineral wool insulation led to a significantly faster drying of the underlying masonry than when polystyrene foam is used. This difference is greater when insulating masonry like AAC is used or when the interior lining is rather vapour tight. For most applications the somewhat slower drying out due to poystyrene foam is only of practical importance if moisture sensitive materials are used and other aspects may be more relevant to the choice of insulation material.