Attributes of Bhutanese Conifer Timber for Optimal Application in the Building Industry

Abstract

Timber and the building industry present a mutually beneficial opportunity. Timber provides a viable means to decarbonise the building sector, while the building industry offers a scalable pathway for high-value application of timber resources.  Rich in forests, Bhutan is well placed to harness these benefits from the use of timber in the building industry.  However, timber exhibits great variability in its properties. Its use as a reliable building material requires a systematic characterisation process to ensure safety and enable optimal utilisation. This paper presents the first-ever findings on the key properties and attributes of two species of fir and hemlock. The physical attributes of knots, expressed as the ratio (tKAR) of the largest knot diameter to the width of the samples and rate of growth (RoG) as the average width of the growth rings, were recorded. The density and bending strength (MoR) were then determined in accordance with the EN 408 and EN 384 standards. The maximum tKAR for fir was 0.5 and 0.6 for hemlock. The largest RoG for fir was 5.0mm and for hemlock 2.5mm. Characteristic (5th percentile) density of 362.84kg/m³ and 462.5kg/m³, and MoR of 14MPa and 7MPa were obtained for the fir and hemlock samples, respectively.