The paper contains a discussion that concerns a problem of safe utility of residential buildings, made in a second half of the 20th Century in a semi-industrialized technologies. The main topic is a durability of connections between cover and bearing layers in sandwich precast walls. A loss of capacity of such connections will not threaten directly the safety of these buildings, but may cause a detachment of cover layer from the precast sandwich wall. The versatility of insulation technologies solutions will not be always beneficial for the partitions in view of physical processes [1], that takes place inside the partitions and impact of these processes on corrosion in building materials.

Keywords: thermo-modernization, corrosion, partition durability.