Colonnades – Vatican City, Vatican City State
In September 1999, the cleaning appliances manufacturer Kärcher officially presented the cleaned Bernini's colonnades to the Vatican. The project lasted around 10 months in total. It was the first time that a new kind of spray process had been used on such a large scale. This enabled Kärcher's hitherto most extensive cleaning project (284 travertine columns and 88 pilasters with an area of over 25,000 m²) to be carried out within an economically feasible time frame, without having to cut corners in terms of conservation.
The spray technique is exceptionally flexible: all of the cleaning factors (spray agent, water, steam, pressure and temperature) can be varied to an almost unlimited degree. This means that not only can all facade surfaces be treated and all types of dirt removed, but a high area performance can also be achieved.
In cleaning the colonnades, Kärcher wanted to contribute to the preservation of this historic Roman structure and at the same time to put its expertise to the test once again by overcoming such a challenging cleaning task.
Kärcher gave the 284 columns and 88 pilasters of Bernini's colonnades on St. Peter's Square a thorough and gentle clean. Here you can see the cleaned columns.