I colori del Bianco Calce: restauro conservativo o manutenzione ordinaria?

The contribution illustrates the results of a research launched in 2012 with C.I.T.E.R.A. “Sapienza”, Rome and continued in the experiences of critical-conservative restoration work on architectural monuments located in the “lime cities” of Puglia. The research collects data of an archival-documentary and practical nature, referring to the processing of slaked lime, as a surface finish applied pure or with pigments on the wall surfaces of the extrados and intrados. The territorial area embraces the urban and rural realities of the Murgia dei trulli; the use of traditional construction techniques of lime milk finishing is the main theme. We wonder about the genesis, evolution and permanence of this technique; on the chemical-physical characteristics of calcium carbonate cooked and “cured” in water; on the conceptual nuances at the base of which the current debate on the “conservative restoration” of the whitewash or its ordinary maintenance revolves. Also through comparisons with Mediterranean geographic realities (Egypt, Turkey, Morocco, Greece, Croatia, Spain), we ask ourselves about the future of the “skin” of buildings veiled in lime. Intervention categories are hypothesized that are based on processes of direct knowledge (construction sites-schools) and active citizenship.