Forms and factors of deterioration of urban art murals under humid temperate climate; influence of environment and material properties

Abstract

This study describes the different alteration forms in 25 street art murals created between 2007 and 2018 on different substrates and located in different cities in NW Spain. The deterioration forms described affect the entire layer of the paintings as well as the substrates, with the most common being loss of colour (fading), loss of the pictorial layer -with or without loss of part of the substrate and biodeterioration. Physical, chemical, mineralogical and micromorphological analyses of samples from 10 murals revealed that (1) the deterioration mechanisms are related to environmental conditions and also to the inherent properties of the painting materials and to paint-substrate interaction, (2) the deterioration is closely associated with inherent aspects of urban art and (3) the loss of the pictorial record sometimes occurs in a very short period of time. The study findings highlight the need for preventive conservation measures in artworks (generally commissioned) that are intended to last.Graphical