Facade treatments of historical buildings: Limiting the risks

The usefulness of treatment of facades of historic buildings and especially those with the status of listed monument is often discussed. Surface treatments of facades comprise a range of treatments, from water repellents to consolidants and anti-­graffiti coatings. Even facade cleaning can be considered a facade treatment. Treatment of monuments and historical buildings is often subject to dispute for both ethical / aesthetical and for technical reasons. In fact, even though often advertised as reversible, surface treatments permanently alter the characteristics of the materials they are applied upon. Treatments of buildings can therefore be seen as a change of the original characteristics of the materials, thus leading to loss of information and affecting their historical value and their aesthetic appearance. During the 20th century chemistry has become increasingly important for conservation and research has been addressed towards the in-­situ treatment of materials, 54 with the aim of delaying their natural decay process. In this scenery, at the beginning of the 1960’s, the first synthetic polymers (water repellents and consolidants) appeared on the market.