In 2011, the final touches were put to this 22 year project. Over the years cleaning techniques had evolved so much that a final touch was required. The total area of the wooden vaulting was 645 m² and comprised no fewer than 1920 planks. The removal, restoration of the wood, fixation, cleaning and retouching of the painting, including replacing just one plank, took an average of three days. This involved a total amount of work of more than 5500 man-days.
Definitely painstaking work, and then to think that according to the archives, the painting itself took only one year.