Restoration of the Sistine Chapel frescoes smoke and exhaust fumes of the city, being "much dirtier than the ceiling proper". The building was a little unstable and had already shifted considerably prior to Michelangelo's work of 1508, causing cracking of the ceiling, the crack in the "Judith" pendentive being so large that it had to be filled with bricks and mortar before painting. The upper part of the ceiling provided Michelangelo an irregular surface due to cracks and water seepage. Continued ingress of water from the roof and from unroofed exterior walkways above the ceiling level had caused seepage which carried down salts from the building
Restoration of the Sistine Chapel frescoes had the courage to commence the restoration process, and thanks not only those who visited the restoration while it was in progress and gave the benefit of their knowledge and experience, but also those who were critical of the enterprise. Pietrangeli made acknowledgement that these people spurred the team on to punctilious documentation so that a full report of criteria and methods should be available to those who are interested, both in the present and the future. Restoration of the Sistine Chapel frescoes The conservation-restoration of the frescoes of the Sistine Chapel was one of the most significant conservation-restorations of