Patina on historic buildings : values, dilemmas and challenges

Abstract

Ageing is a phenomenon which may be seen and appreciated on masonry buildings in a variety of forms. These different processes cannot be stopped, however they may be intervened upon. The way these interventions are conducted generate many questions and challenges, which this study will examine with particular reference to Globigerina Limestone buildings in Malta, where the number of conservation interventions on facades of historic buildings has steadily increased over the past two decades. The study starts with a review of the literature on approaches to, and definitions of patina in order to better understand the role and attitudes of different professions and stakeholders in this regard. Interviews were undertaken with architects to document their views of patinas and their methods for and approaches to the issue of cleaning of facades of historical buildings. An online survey, aimed al gaining some understanding of the perceptions of the general public, was carried out. The results of the interviews and the online survey are compared and analysed. It was concluded that although architects know that patina is something which has value, there is no clear consensus on what should and should be included in the category of patina that should be valued and preserved. The key challenges which architects face while carrying out a project to clean the facade of a historic building are identified. The results were then used to develop recommendations on best practice in the cleaning of facades of historical Globigerina Limestone buildings.