COMPARATIVE MEMO regarding some technical issues, referring to the thermal rehabilitation program of blocks older than 20 years in Romania One of the most important factors, which argue, the use of the LOOSELY VENTILATED INSULATION SYSTEM over the ADHESIVE INSULATION SYSTEM, is the high carbonation factor of the facades of blocks that are at least 20 years old.

Carbonation means the in-depth degradation of the plaster and even the concrete from the outer layer of the walls, which make up the facades of the blocks, due to the action over time and the high concentration of CO2 and SO2 in urban areas. The adhesion to these surfaces of ordinary mortars, based on Portland cement and sorted aggregates from river ballast (which also contains ballast resulting from freezing rocks – it crumbles after 2-3 cycles of freeze-thaw), hence the warranty offered on facades insulated with polystyrene is 2 years. The loosely ventilated system is preferable, as it has the advantage of aging (similar to carbonation), after 20-30 years from its putting into use. For the polystyrene and wool (classic) system to be adequate, the plaster must be cleaned and redone, as well as the use of a mortar with appropriate chemistry, which should contain quality synthetic resins in the right amount, quarry quartz aggregates, which makes it almost impossible to verify the quality of the materials used and implies very high real costs for implementing the system.