Timber and stone are the oldest known building materials. Our most ancient buildings are characterised by their use. So it is no surprise that an engineer looking after historic fabric will regularly encounter the need to repair timberwork.
The greatest threats to the structural integrity of timber are from attack by rot and insect; therefore, in the damp British Isles, those working in conservation will often need to reach for the sketchpad to record and re-detail areas damaged by the effects of moisture.
Interventions to historic timberwork are also necessary when a building is converted. This happens, for example, when floor joists are reframed or loading is assessed for a new use. While philosophically this is different to a simple repair, it nevertheless requires similar skillsets to achieve the best, most sensitive results.
This article looks briefly at these matters, first from the aspect of conservation philosophy and material choice to establish some ground rules, and then by showing some of the details typically in use in the UK today. In order to focus on these, it does not consider survey and diagnosis.