The ceiling of the chapel is a flattened barrel vault springing from a course that encircles the walls at the level of the springing of the window arches. This barrel vault is cut transversely by smaller vaults over each window, which divide the barrel vault at its lowest level into a series of large pendentives rising from shallow pilasters between each window. The barrel vault was originally painted brilliant-blue and dotted with gold stars, to the design of Piermatteo Lauro de' Manfredi da Amelia. The pavement is in opus alexandrinum, a decorative style using marble and coloured stone in a pattern that reflects the earlier proportion in the division of the interior and also marks the processional way from the main door, used by the Pope on important occasions such as Palm Sunday.
the ceiling of the chapel is a flattened barrel vault springing from a course that encircles the walls at the level of the springing of the window arches this barrel vault is cut transversely by smaller vaults over each window which divide the barrel vault at its lowest level into a series of large pendentives rising from shallow pilasters between each window the barrel vault was originally painted brilliant-blue and dotted with gold stars to the design of piermatteo lauro de' manfredi da amelia the pavement is in opus alexandrinum a decorative style using marble and coloured stone in a pattern that reflects the earlier proportion in the division of the interior and also marks the processional way from the main door used by the pope on important occasions such as palm sunday