Werktrockenmörtel : Kalkputz in der Denkmalpflege

The hardening process of lime renderings applied on exposed test walls with different orientations has been investigated by drilling resistance tests. Three traditional mortars and two ready-mix mortars with a small addition of cement (ca. 5%) have been examined. The best results were obtained with the ready-mix mortars with additives of water-repellent, air bubble forming, and water retaining agents. Lime renderings without additives and especially without hydraulic binder are not recommended either in general or for heritage buildings.