Strength grading and the end user – lessons from the SIRT project at Napier University

Ridley-Ellis, Daniel, Moore, John and Lyon, Andrew J (2008) Strength grading and the end user – lessons from the SIRT project at Napier University. In: Conference COST Action E53 “End user’s needs for wood material and products” , 29th - 30th October 2008, Delft, Netherlands.

Available under License Creative Commons Attribution Non-commercial.

Download (314kB)
Official URL:


The paper reviews the research that has been undertaken by the Strategic Integrated Research in Timber (SIRT) project at Napier University, with reference to the technologies, techniques and approaches required to grade the UK’s timber resource according to the real needs of the end user. The project has been operating since 2004, and has made significant progress in understanding the nature and variability of UK-grown Sitka spruce.

It has been seen that UK-plantation Sitka spruce can yield timber of grade C24, and that with the right breeding and silviculture it may indeed be economic to aim higher than the current C16 production. Conversely it has also been seen that there are geographic areas where the current resource is of marginal quality for constructional use. In these circumstances it is important to know how to find the best wood within each tree, and how to divert unsuitable material at an early stage. Crucially, it is important to ensure grading of such marginal material is actually delivering what the end user wants.

Indeed a number of important general questions remain about the suitability and robustness of current grading practices. These questions are partly informed by data that has been gathered to-date, but more research is needed and possible approaches are presented for discussion. These include questions around: the variation in the resource and the implications for sawmillers and end users; the potential and pitfalls for resource segregation; and the ‘non-mechanical’ properties that affect utilisation of graded timber (principally distortion and knots).

Item Type: Conference or Workshop Item (Paper)
Related URLs:
Additional Information: Electronic fulltext of the conference is available from: .
Uncontrolled Keywords: Forestry; Timber; Engineering wood; Strength; Grading techniques; Sitka Spruce;
University Divisions/Research Centres: Faculty of Engineering, Computing and Creative Industries > School of Engineering and the Built Environment
Dewey Decimal Subjects: 600 Technology > 690 Building & construction > 694 Wood construction & carpentry
600 Technology > 690 Building & construction > 691 Building materials
600 Technology > 620 Engineering > 624 Civil engineering
600 Technology > 630 Agriculture > > 634.9 Forestry
Library of Congress Subjects: T Technology > TA Engineering (General). Civil engineering (General)
S Agriculture > SD Forestry
Item ID: 2521
Depositing User: Dr. Daniel Ridley-Ellis
Date Deposited: 07 Apr 2009 11:27
Last Modified: 23 Mar 2015 14:43

Actions (login required)

View Item View Item


Downloads per month over past year

View more statistics

Edinburgh Napier University is a registered Scottish charity. Registration number SC018373