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
Sistine Chapel ceiling cleanly defined outlines make each subject easily visible from the floor. Despite the height of the ceiling, the proportions of the "Creation of Adam" are such that when standing beneath it, "it appears as if the viewer could simply raise a finger and meet those of God and Adam". Vasari tells us that the ceiling is "unfinished", that its unveiling occurred before it could be reworked with gold leaf and vivid blue lapis lazuli as was customary with frescoes and in order to better link the ceiling with the walls below it which were highlighted with a great deal of