ABSTRACT
York Minster is over 500 years old and requires very expensive maintenance to ensure its existence for future generations. It is composed of a wide variety of materials, which have been subjected to erosion. The external fabric of stone has been eroded both by natural weathering and by chemicals put into the atmosphere by man’s actions (Figure 1.1). Winning the battle between the Minster and its environment lies not only in reducing atmospheric pollution but also in the replacement of damaged stone. This replacement is not a simple matter because, although there is fresh stone in abundance, the continual replacement of stone can undermine the integrity of a building by causing the structure to become unstable. At York Minster the stonemasons try, as far as possible, to incorporate all old stone into any repair work because there is the danger that if too much fabric is replaced there could be a serious loss of authenticity (Brimblecombe and Bowler 1990).
