## 4 Findings
### Standard and Marine Service Conditions
As discussed above, the predicted life expectancy of a component is determined by the typical deterioration path intersection with the MRCP. Two threshold levels of minimum required component performance were considered [10; 11; 12; 30], as follows:  
(1) MRCP = 60%, for a high service standard of CP, for instance, in public or corporate buildings. (2) MRCP = 40%, for moderated or low service standards, where the owner prefers to minimize maintenance costs while compromising the service standard of the exterior cladding. Thus, the LE for MRCP 60 and 40 may be derived from the intercepts between the typical deterioration path curve and the 60 and 40 lines of performance levels, respectively. The confidence limit of the service life prediction was established at 80%, as recommended by ISO 15686 (2011) [13]. The standard life expectancy (SLE) for wet-fixed stone cladding under standard service conditions was previously discussed by [PERSON] and [PERSON] et.al. [12], who reported values for MRCP\({}_{60\%}\) and MRCP\({}_{40\%}\) of 44 and 64 years, respectively. In this study, the reference service life of exterior dry-fixed stone cladding under standard service conditions was investigated in order to compare the values to the standard life expectancy of wet-fixed stone cladding. In addition, the typical deterioration patterns of both cladding methods in marine environmental conditions were examined in order to estimate the LELC. The typical deterioration curve for dry-fixed cladding under standard service conditions is shown in Figure 5. It expresses the regression analysis of 24 data points in a linear degradation process. The moderate decline in cladding performance reaches MRCP\({}_{60\%}\) and MRCP\({}_{40\%}\) levels after 59.5 and 88 years, respectively. It should be emphasized once more that the service life cycle expectancy at MRCP\({}_{40\%}\) is marginal with respect to the component performance of exterior stone cladding and involves inherent hazardous defects, i.e., delamination of stone plates, cracks in cladding, and detachment of complete stone plates. Figure 6 shows the typical deterioration progression for wet-fixed stone claddings subjected to a marine environment. The life expectancies (LEFCs) for MRCP60% and MRCP40% were found to be 35 and 54 years, respectively. Calculating the life expectancy limited coefficient according to Equation (1) gave LELC = 0.79-0.84, indicating the strong  
Figure 5: Deterioration pattern for dry-fixed stone claddings under standard service conditions. impact of marine environment service conditions on the service life expectancy of the wet-fixed exterior stone cladding. Table 6 summarizes the typical service life expectancy of wet-fixed exterior stone claddings exposed to the various service conditions. These findings are valid if no differences in the weather conditions occurred, compared to the characteristics at the time of analysis or if a constant increase of the sunny days number occurs, or the temperature, or the number of freeze-thaw cycles per year--and the weathering conditions, such as the salinity of water, increase (and accordingly the salinity of the air and thus the degree of influence on the anchorage system of the exterior stone cladding wall). It should be emphasized that the predicted service life intervals, MRCP\({}_{60\%}\) and MRCP\({}_{40\%}\), were deduced by extrapolation of the linear regression lines of the predicted life expectancy, as well as the lower and upper prediction intervals lines. Therefore, further research with an extended range of service life is recommended in order to validate the results. Finally, the typical deterioration pattern for dry-fixed stone cladding exposed to marine environment is presented in Figure 4. The relatively moderate gradient of the average regression line yields life expectancies (LEFC) of 55 and 85 years for MRCP\({}_{60\%}\) and MRCP\({}_{40\%}\), respectively. In this case, calculation of the life expectancy limited coefficient