Active conservation of ceramic building materials: removal of lichens on roof tiles by laser and biocides treatments

Abstract

Very recently, in monumental cities, certain conservational practices tend to use ancient/traditional roof tiles in the restoration of Heritage buildings. Numerous studies have been undertaken to remove lichens on stones. However, little has been done to date to study lichens removal from ceramic materials, despite the fact that they are commonly colonized by different lichen communities. The main goal of this contribution is making a diagnosis of alterations that lichens may cause in ceramic materials, as well as to determine the possibilities of removal by treatments based on laser irradiation and use of biocides.