Different degrees of stone decay on the inner and outer walls of a Cloister

Avila is a city located on the Central Meseta of Spain whose climate follows a continental trend with strong daily fluctuations in temperature, that produce stresses in exposed materials owing to processes of dilation/contraction. Specially in heterogeneous materials such as granite. These stresses lead to microfissures and even surface sand formation (arenization) decay. The different degrees and types of decay observed in exposed and protected materials inside the Cathedral Cloister microenvironment in Avila are largely due to the above phenomena. In the present study, the environmental characteristics at three different points of the Cathedral are analyzed. One outside the building (E) and the other two inside it, at the Southern (I–S) and Northern (I–N) ends of its East gallery. At these points, the fluctuations in relative humidity and temperature were found to be very low, accounting for the lower degree of decay of the stone used to construct the building.