Life Cycle of Repair Works of Rock Based Facades

Jukka Piironen, Esko Sistonen, Seppo Huovinen Life Cycle of Repair Works of Rock Based Facades Date: 30/06/2003 Pages: 97 p.+ app. 39 p. Helsinki University of Technology Laboratory of Structural Engineering and Building Physics Rakentajanaukio 4, 02150 Espoo ESPOO ISBN 951-22-6654-7 ISSN 1456-4297 The aim of this study was to make a life cycle analysis of the repair methods of the rock based facades and to specify the main factors and their risks affecting on the length of the service life of the repair. The second aim was to study how the repair methods can be developed to make certain to reach the desired length of the service life. The problems of the facade repair methods were clarified by the life cycle analyse. The structures studied were cladding systems with the light gauge steel sheets and panels, cementitious panels, external wall insulation faced with plastering and concrete coatings. The life cycle costs compared with the length of the service life of the repair was studied. The service life of the cladding system with the light gauge steel sheets and panels, cementitious panels and external wall insulation faced with plastering will be determined by the aesthetic symptoms. Basing on the field research of the repaired facades proposals for actions to extend the service life of the repair methods were presented. Theoretical estimations of the service life was illustrated by stochastic methods. Examples of the method is presented in appendixes. The graphs of these examples may be used as a instrument to make the life cycle analysis and planning. Reliability of the estimations of the service life is governed by the quality of the deterministic equation and the selected distribution model and by the defectiveness of statistical data. The problem with the simplified equations is that they do not take into account several simultaneous deterioration defects and their interaction. A life cycle analysis for a residential building located in Espoo was made. Cost of repair for seven alternate repair methods was calculated. The repair methods of the calculation examples were the suggest ones in the condition survey made for the building. The changes in affordability ranking of the repair methods caused by the changes in length of the maintenance periods was studied in the sensibility examinations. The effects of the additional wall insulation on the heating energy consumption was studied in three real estates. The systematic of the condition survey for facades with the external wall insulation faced with plastering and cladding systems should be improved. Condition surveys made for the facades repaired by these methods will help to clarify the most dominating deterioration defects and to make service life models. This will furthermore guide to make more reliable life cycle analyses.