Guidelines for On-Site Assessment of Historic Timber Structures

In the scope of European Cooperation in Science and Technology-Wood Science for Conservation of Cultural Heritage (COST IE0601-WoodCultHer) (available at http://www.woodculther.org) it was agreed to produce Guidelines for the Assessment of Historic Timber Structures, covering the principles and possible approaches for the safety assessment of old timber structures of historical relevance that could be used as the basis for possible European Standards, as discussed with CEN/TC346 (Conservation of Cultural Heritage). This approach was targeted at all those concerned with the conservation of heritage buildings. These guidelines should also help decision-making regarding the need for immediate safety measures. The aim is to guarantee that inspection and assessment measures provide the necessary data for historical analysis, structural safety assessment, and planning of intervention works, while having minimal impact on the building fabric (the original materials, structural systems, and techniques).This article provides information on the criteria to be used in the assessment of load-bearing timber structures in heritage buildings. It covers the preliminary assessment (desk survey, preliminary visual survey, measured survey, structural analysis, and preliminary report), as well as the detailed survey of timbers (with a special emphasis on visual strength grading on site) and carpentry joints. The subsequent diagnostic report and the detailed design of repairs are outside its scope.