On-site Radioscopic Qualitative Assessment of Historic Timber Structures: Identification and Mapping of Biological Deterioration of Wood

The recent development of portable, battery-charged x-ray tubes and digital detectors has made digital radioscopic examination of wooden buildings a realistic option. Lack of experience with the often very complex radiographs of building structures makes the interpretation of such radiographs difficult. A set of radiographs of wood in different, identified conditions was established for use when interpreting radiographs of wood in unknown condition.

This article presents radiographs of a trestle-framed building. The recordings were done in areas where the condition of the wooden elements was known in advance, either on the basis of dendrochronological drill samples or because the building element had been replaced recently and the wood was sound. The radiographs were compared with NIKU´s collected guideline radiographs and discussed with respect to the information they provide about the wood’s condition. Finally, we discuss radioscopy as a supplement to traditional methods of building surveying.

The authors took all of the photos and radiographs (©NIKU). The radiographs are shown as “shadow” images—materials of higher density are seen lighter than materials of less density, as long as they are of same thickness.