Influence of the Infiltrated Rainwater on the Degradation of the Inner Wall in Hagia Sophia, Istanbul

Abstract

Hagia Sophia in Istanbul has been suffering from severe degradation of the walls mainly due to salt crystallization. The objective of this research is to elucidate the degradation mechanism and propose a suitable method for preservation. From field surveys and numerical analyses of heat and moisture behaviour in the walls, it was found that high moisture—primarily due to the infiltrated rain water—generally leads to the degradation of the inner and outer walls. Moreover, it is highly possible that evaporation, mainly at the middle-layer mortar, causes salt crystallization and exfoliation of the inside stucco wall surfaces.