The Colosseum in Rome is being cleaned and restored so that the five million tourists who visit the site every year will finally see its true colours.
It has been covered in a layer of black pollution for many years, and this has been removed by hand, inch by inch, without the use of harsh chemical solvents which could damage the stone. The only product used is water.
Gisella Capponi, the restoration site manager, outlined how the cleaning was done: “We developed a water spray system, equipped with nozzles positioned 40 centimetres apart. They are then positioned just beside the area to be treated, so that there is no mechanical action or contact with the stone. There is only liquid contact.”
Once the cleaning was complete, loose flakes of travertine were glued back into place. Travertine is a kind of limestone, usually formed by rapid precipitation of calcium carbonate, often near a hot spring or limestone cave. The colour ranges from white to rust.
Capponi continued: “Once these pollution deposits have been made soluble, they have to be removed. So the restorers remove them using just a soft, small brush. While brushing they continue to spray water to wash the dirt away.”
The restoration work started in the summer of 2012 and is expected to be completed in 2016. The 25 million euro project has been financed by Italian businessman, Diego Della Valle, founder of the luxury leather goods company, Tod’s.