Conservation compendium. Part 7: Imposed load in historic buildings: assessing what is real

The design of concrete slabs and beams is not generally affected by fire design requirements. However, these can be a governing factor in the sizing of columns, particularly in multi-storey buildings. This article therefore concentrates on the guidance given in Eurocode 2 on the sizing of concrete columns for different fire resistance periods.

Historic buildings and structures, like any other, move to some degree, whether due to thermal effects, changes in moisture levels in the structural fabric, influences on the founding subsoil, or environmental forces. The key question for the conservation engineer is to determine whether the movement is progressive and presents a risk to the structure. This article introduces engineers to the various techniques available to monitor movement in historic structures, from simple manual techniques which are less commonly used today, to sophisticated electronic systems. The form of monitoring will depend on the nature of the assumed movement, the funds available, and the possible consequences if the movement is progressive.

This article focuses on the phenomenon of 'bond timbers', which were commonly built into masonry walls from the late 17th to the early 19th century. Guidance is offered to engineers who may encounter these when working on an existing building.