Investigating the effects of humidity and salt crystallisation on medieval masonry

摘要

An investigation of the effects of humidity and salt crystallsation on medieval masonry has been undertaken at the parish church of Walpol St Andrew, Norfolk, with the intertion of establishing a relationship between changes in environmental conditions and levels of stone decay. Masonry within the church has been contaminated with sodium chloride salts, which are undergoing cycles of crystallisation/dissolution in response to fluctuations in relative humidity corresponding to the equilibrium relative humidity of the salt.