## 4 Deterioration Patterns  
Photogrammetric observations were used to adapt deterioration patterns to the facades of the three heritage buildings analyzed. As observed, deterioration is only present at the bottom parts of the facades. Rectangular and triangular deterioration patterns were assumed [7] as the best fit to the photogrammetric data. Figure 3 shows a buttress of the San Jeronimo Monastery in the City of Granada. Three cross-sections, obtained with photogrammetry, were chosen as representative of each one of the sides of the buttress. Based on a statistical analysis of the three cross-sections, a rectangular deterioration pattern was adjusted to the current state of the buttress, as shown in Figure 3. Figure 4 shows part of the main gate of Del Carmen Church in Alhama de Granada, where a triangular deterioration pattern was adjusted.  
Average patterns of the analyzed buildings were obtained. Table 2 summarizes the main parameters deduced at the three monuments studied. Except for the buttresses of the San Jeronimo Monastery, triangular deterioration patterns were considered, as suggested in [22] for SP calcarenite in Granada. The mean degraded area and the standard deviation of the adjusted deterioration patterns are shown in the last two columns of Table 2. It can be observed that there is less deterioration at Nuestra Senora del Rosario in Velez de Benaudalla, a location near the coast. The most severe deterioration is found on the buttresses located behind the apse of the San Jeronimo Monastery, probably caused by the heterogeneity of the SP calcarenite.  
In the seventh column of Table 2, the value of equivalent constant mean recession (R), calculated by dividing the average deteriorated area by the height affected for degradation, is indicated. Table 2 shows that the constant mean recession (R) at del Carmen Church in Alhama is 21.4 mm, which leads to an average loss of 0.05 mm/year. In the case of the San Jeronimo Monastery, the average loss is 0.024 mm/year, while at Nuestra Senora del Rosario Church (near the coast), it is 0.00091 mm/year.  
Figure 2: Variations in weight (\(\Delta\)W in %) during the freeze–thaw cycles for three water content levels studied.  
In light of Tables 1 and 2, it can be concluded that the number of days with temperatures below zero is a more important factor in the deterioration of SP calcarenite than relative humidity. Furthermore, the trend in the on-site observed data from the three historical heritage buildings matches the laboratory data for the SP calcarenite. This observation is compatible with the fact that, due to the high porosity of SP calcarenite, dew--which penetrates the rock every day--could be a factor that favors the deterioration of this stone when it is subjected to daily freeze-thaw cycles.  
Figure 4: Main gate of Del Carmen Church in Alhama de Granada: (**a**) location of the main gate; (**b**) elevations studied—S1, S2, and S3; (**c**) deterioration patterns—the yellow outline shows the adjusted triangular deterioration pattern.  
Figure 3: Current state of a buttress in the San Jerónimo Monastery: (**a**) location of the buttress; (**b**) buttress analyzed—S1, S2, and S3 indicate the elevations studied; (**c**) deterioration patterns—the yellow outline shows the adjusted rectangular deterioration pattern.