Sitka spruce (Picea sitchensis) is the United Kingdom’s main commercial tree species accounting for nearly one-third of the UK's total woodland area and half of its conifer estate. Sawn timber from this species readily grades to the C16 strength class, but there are factors beyond the structural grade that can influence its acceptance as a construction material. This paper summarises the results from resource characterisation studies that have investigated the properties of Sitka spruce at the standing-tree scale down to the scale of a few microns. These studies have substantially improved the understanding of the impact on mechanical performance of structural timber of factors at the micro-structural level (e.g. cellulose structure and abundance) and at the forest-level (e.g. genetics, the environment and forest management). End-user requirements for timber are discussed in terms of what is, and is not, provided by current grading practice and some of the main misconceptions about UK-timber are challenged.
Ridley-Ellis, D., Moore, J., Lyon, A. J., Searles, G. J., & Gardiner, B. A. (2009). Strategic Integrated Research in Timber: Getting the most out of the UK's timber resource. Non-conventional Materials and Technologies,