Wood–water relations of chestnut wood used for structural purposes

Abstract

Hygroscopic properties and water vapour permeability of chestnut (Castanea sativa Mill.) wood were studied using saturated salt solutions, and the results were analyzed using the Hailwood–Horrobin model. At 20 °C/65 % the equilibrium moisture content (MC _eq ) and density were 11.5 ± 0.1 % and 576.6 ± 10.2 kg m⁻³, respectively, and the fiber saturation point was 20.83 %. The average water vapour permeability was 0.320 kg m⁻¹ s⁻¹ Pa⁻¹10⁸, lower than that of Radiata pine (0.726 kg m⁻¹ s⁻¹ Pa⁻¹10⁸). Furthermore, there was no difference in permeability between tangential and radial cuts. This low permeability is explained by the scant development of the multilayer of the Hailwood–Horrobin model. This is attributed to the wood extractives, which reduce the void space and hindered condensation. Chestnut wood has different vapour sorption and vapour permeability than conifers normally used in construction.