# Operationalisation of Building Inspections and Repair: Systematisation-Based Approach
## 4 Discussion
### Most Common Types of Repair Techniques  
Section 3.2 establishes separately significant repair techniques to prescribe while rehabilitating roof claddings, facade elements/claddings and floorings. In roof claddings, \"R-A1 Cleaning\" is relevant for many common defects, mainly associated with dirt accumulation and biological growth, both on the current surface and drainage system, which are very frequent and of paramount importance for the good performance of the building envelope. In facade elements/claddings, \"R-A1 Cleaning\", \"R-A2 Application of a protective coat (paint, varnish, water-repellent, antifungal, biocide)\", \"R-A11 Replacement or reapplication of the cladding/glazing (partially or completely)\", and \"R-A12 Application of a new (adequate) cladding/finishing coat over the existent/replacement\" were identified as the most transversal repair techniques, all mostly referring to the outer layers of the cladding system, considering the prevalence of superficial defects (moisture, dirt, disaggregation, cracking, biological colonisation, vegetation growth, efflorescence/cryptoflorescence). As for floorings, \"R-A11 Replacement or reapplication of the cladding/glazing (partially or completely)\" is highlighted, particularly because it can solve a large span of common defects in these elements/materials. Given these results, it is worth noting that repair techniques have specific needs in terms of materials, workload, and process of application depending on the building element/material. Nevertheless, given the categorisation of [PERSON] et al. [32], some repair techniques seem to heal a lot of the most frequent defects. Those techniques are cleaning (R-A1), application of a protective coat (R-A2), partial or complete replacement/reapplicationof the cladding/flooring (R-A11), and replacement or application of a more suitable cladding/flooring (R-A12). Furthermore, the specificity of repair techniques according to building elements/ materials makes it more complex to perform a full analysis of the use of involved resources. To perform a preliminary framework for that kind of analysis, the application procedures for some materials were analysed according to freely available data [39]. These data were adapted to an LCA-based cradle-to-gate approach [38]. This is the first analysis of the kind in the literature, since usually, LCA uses standard data about the service life of materials, not specifically considering the maintenance procedures involved. The relevance of such an analysis is attested by some of the results presented in Section 3.2.3. For instance, to properly clean a flat roof, 10 L/m\({}^{2}\) must be used, which, in larger buildings, may refer to an annual expenditure of more than 70,000 L of water (a rough estimate based on the size of Portugal's largest hospital). Besides the expenditure of water, its eventual contamination during cleaning procedures should be considered, as well as methods to prevent it from reaching public mains. Additionally, the cost of cleaning a roof may also be high, taking into account that such a procedure should preferably be performed bi-annually (for the drainage system) and yearly (for the whole roof) in a proactive preventive approach [74]. If the same example is considered, but with a metallic pitched roof, the cost would have to comply with 191 h of labour of construction workers to clean gutters (EUR 4202), plus 910 (EUR 23,831) of cleaning agent, plus 3829 h of labour of construction workers to clean the current surface of roof tiles (EUR 84,238) (costs based on data from CYPE Ingenieros S.A: [27] and retail prices in Portugal in April 2024). An annual cost of more than (not all costs are considered) EUR 8404 to clean gutters and EUR 112,271 to clean the whole roof are impactful in the service life cost of a building, thus affecting the economic component of life-cycle assessment. In different orders of magnitude, cleaning procedures are also impactful in terms of cost and resource use per intervention in facades.