Abstract

This article thoroughly documents the focus, long-term monitoring, and survey of the condition of a unique early Gothic wooden ceiling from the 13th century in Zvíkov Castle in the Czech Republic. Through long-term monitoring of climatic parameters, wood moisture, and the movement of ceiling beams, this paper described how wood constantly works, that is, swells and shrinks during a single annual cycle. At the interface of the ceiling beams and the masonry, the ambient temperature ranged from 2.75 °C to 31.75 °C, and the relative humidity of the air from 38 to 93%. The condition of the walled-in beam ends was assessed by resistance drilling and endoscopy. Out of a total of 16 beam ends, 7 ends are completely degraded by brown rot fungus. The condition of the ceiling structure is not good, even in the case of the boards covering the ceiling. Here, the sapwood parts are additionally damaged by the beetle Anobium punctatum which, in combination with rot, has broken down the wood into crumbling matter. High static load due to a massive embankment 35–50 cm thick, two layers of fired paving, and occasional loading causes the wood to deteriorate over time and requires urgent stabilization. The final section reflects on the approach to sustainably securing the uniquely preserved structure. Finding the optimal solution represents a challenging decision-making task between a conservation intervention of external support with minimal intervention in the existing structure and the structural restoration of individual elements, requiring disassembly and reassembly of the structure.

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