Historical domes versus wood preservation methods

The paper collates various solutions of the structural systems of historical domes made from solid wood by arranging them into a typological series including domes of a span from several up to 67.0 metres of the horizontal projection’s diameter. Many of them were destroyed in fires or out of human ignorance. Preservation methods, in which modern materials and technologies appear, determine the wood durability in a construction. Through using the analogy of wood structure to fibrous composites, the reduction in the carrying capacity of compressed wooden bars due to a damage of parenchymatous cells (as a visco-elastic matrix) in consequence of having applied improper preservation methods and preparations was discussed. The selection criterion of thermo-insulating materials embedded in a close vicinity of wood was formulated. The materials of a constant coefficient  within the range of natural variations of the moisture content of ceilings and roofs were recommended. The materials of full, not absorbable fibres, such as rock wool and glass wool, do not meet this criterion.