# Operationalisation of Building Inspections and Repair: Systematisation-Based Approach
## 3 Results
### Most Common Diagnosis Methods to Prepare an Inspection
#### 3.1.1 Diagnosis Methods in Roof Claddings  
In Table 11, the most relevant inter-defects correlations in roofs are identified, referring to different relationships between defects \"A-A1 Leakage damp\", \"A-A2 Surface moisture\", \"A-A3 Dirt and accumulation of debris\", \"A-C3 Fracture or splintering on the current surface\", \"A-D1 Flaws in tail-end elements\", and \"A-D12 Ponding/insufficient or excessive slope in roofs\". According to the data of [PERSON] et al. [40] adapted to the harmonisation of the classification of defects [33], none of these defects represent the top most detected defects in **external claddings of pitched roofs (ECPR)**. Nevertheless, some are commonly found, such as \"**A-D12** Ponding/insufficient or excessive slope in roofs\" (31.9%), \"A-D1 Flaws in tail-end elements\" (31.7%), and \"A-A3 Dirt and accumulation of debris\" (in 28.0% of inspected pitched roofs). As for **flat roofs (FR)**, according to the data of [PERSON] et al. [41], adapted to the harmonisation of the classification of defects [33], defect \"**A-A3**  
Figure 2: Methodology followed to build and analyse correlation matrices to reach the proposed goals (considering the information of [PERSON] [35] and [PERSON] et al. [13]). As for the severity of the set of defects included in the most relevant correlations in roof claddings, data from service life prediction methodologies may be considered. In the case of external claddings of pitched roofs, the severity implicitly associated with the degradation levels for defects by [PERSON] et al. [42] may be used. Of the mentioned set of defects, these authors only take into account \"A-A2 Surface moisture\" and \"A-A3 Dirt and accumulation of debris\", which comprise the defect \"Staining, change in colour, or brightness of the tiles\". This defect is admitted to affect 20% or less of the total area of the pitched roof cladding when it is in good condition (Level 1). On the other hand, if it affects more than 50% of the total area of the pitched roof cladding, then it should be considered moderately degraded (Level 3). [PERSON] et al. [42] use a five-level scale from Level 0 (Very good) to Level 4 (Generalised degradation). [PERSON] et al. [42] also take into account the defect \"A-C3 Fracture or splintering on the current surface\", which is included in the defect \"Cracking/fracture\". If such a defect affects 10% or less of the total area of the pitched roof claddings, it should be considered slight degradation (Level 2). On the other hand, if it affects more than 30% of that area, then the roof has generalised degradation. From the data of [PERSON] et al. [42], it is found that defect A-C3 is considered more severe than A-A2 and A-A3. Nevertheless, it is important to highlight that a roof in very good condition (Level 0) should not have any signs of either of these defects. As for flat roofs, the same kind of analysis cannot be performed. Still, some literature [43] highlights the importance of \"A-A1 Leakage damp\", which may be associated with flashing details (between membranes) due to inadequate installation or improper detailing below the coping cap on parquet walls (where a moisture barrier is required). This cause is actually associated with the defect \"A-D1 Flaws in tail-end elements\". Moreover, \"A-D12 Ponding/insufficient or excessive slope in roofs\" may also be a common problem in flat roofs, according to [PERSON] [43], associated with the incorrect design of the required slope to promote drainage of rainwater. In any case, drains must be checked to guarantee that they are not clogged. Also in Table 11, the results referring to the diagnosis methods associated with the most relevant correlations are presented. It is found that, for roof claddings' inspection, the most likely methods to be used, besides visual inspection, are \"D-A3 Assessment of the slope, flatness, orthogonality, and alignments\" and \"D-C3 Infrared thermography\".