Materials, degradation patterns and conservation-restoration techniques
„We illustrate to students degradation pathologies and their characteristic patterns in natural and artificial stones including brick works and plasters.
Deterioration patterns due to discoloration and deposit are highlighted focusing on differences between coloration, staining and patina – stressing the idea of natural Patina as a value as well as the concept of Patination in restoration.
We exemplify integration techniques especially for missing parts concentrating on the use of colours and mortar in conservation-restoration practice emphasizing the concept of Lacuna as a lack towards stratifications of layers.
Due to limitations to on-site activities orthographic views and cad drawings of the case study are provided to students in advance to fulfil the following tasks:
– recognizing and mapping materials and describing the different manufacturing techniques;
– recognizing and mapping the different degradation patterns by complying with international standards and guidelines (i.e. ICOMOS-ISCS: Illustrated glossary of stone dedication patterns – based on the Italian NorMal – 1/88 Alterazioni Macroscopiche dei Materiali). Here, degradation patterns are represented in a form of graphic drawing, which commonly are accompanying conservation-restoration architectural projects.
– designing conservation-restoration strategies especially for the case study.
Based on the knowledge acquired and date provided, it is expected that students devise their own architectural languages to deal with existing works of art and especially for surfaces lacking integrity with respect to both their aesthetic appearance and their materiality, which is bond to the very nature of materials – thus, to specific manufacturing processes.“
(Roberta and Th Danzl)
„Craqueles are networks of minor cracks, which are also called Crack Networks. The term Crazing should be used to describe the development of a Crack Network on glazed terracotta only. Exclusively, the paint layer of the original Fresco is affected by Craqueles.
Some pigments with their binding media need a certain amount of water to be applied. Therefore, these Craqueles are due to the working process. This phenomenon is a lack of cohesion [ crumbling | flaking ] and therefore is a dynamic and ongoing process that cannot be completely stopped. Becuase of this, nothing should be done about the Craqueles in the Fresco. They can serve an educational purpose and should be considered as a trace of time.
This deterioration process might slow down once the Fresco is protected against weathering.“ (Sabrina)