ABSTRACT
This chapter presents several guidelines for safety developed through a synthesis of examples taken from the author's practice that were either encountered in an unstable condition, or were made unstable by incorrect methods of work. It introduces the concepts of load transfer, level of disturbance, the 'window analogy', and 'safe-to-unsafe' progression work. The modern division between craft and design generally assigns responsibility for safety during the work to the craftsman, and the design for achieving final structural safety to the engineer. Recovery begins as the new work takes a set and begins to re-stiffen the wall and transfer load, ultimately restoring stability. The engineer and the mason should work together to identify the likely level of disturbances. Importantly, the work of structural conservation almost always requires removal of mortar or stones as part of the intervention process. In most ordinary work, there no significant concern; the work may proceed at any pace that suits the mason.
