A guide to appearance grading UK grown hardwood timber
Authors: Ivor Davies & Guy Watt
I am proud to be part of the UK forest industry. Sitting on my desk is the new hardwood appearance-grading guide, which compares more than favourably with the equivalent French and American guides and considering the size of their resource it really is a major achievement.
It seems years since Ivor Davies and Guy Watt shared some of their research on this project and I know there have been difficulties on the way. Congratulations on seeing it through to publication and well done to the eight supporting organisations, I am only sorry not to see the UK Forest Products Association on the list.
The guide starts with a simple introduction followed by an explanation in table form of the appearance grading system used under the heading ‘Grading Criteria’. This is where attempts at grading in the past have so often failed, to understand what all the different features in hardwood look like – you really need to see them and feel them if you like. They have tried to get over the complex variety of features by creating ‘Optional Sub-grades’ and then there is a long list of notes to help you understand each feature. All this leaves us with a grading system that still requires interpretation between specifier and user/buyer.
To me the greatest strength of this grading guide is in the colour photographic example of each grade by species. Over the years there have been many attempts at this, but the printed examples in this guide are outstanding. The way they have brought in the special features in Oak is an example of the care taken. These features are so important for the market place today.
There are five very useful appendices –
- The comparison with European and British standards
- Measurement of sawn hardwood timber, including permitted tolerances and a guide to wastage factors
- An extensive glossary which includes diagrams of the types of log conversion, tables on movement characteristics and a durability classification
- Two tables setting out the properties and uses of UK hardwoods
- Last, but by no means least, a Specifiers and Buyers check list.
The guide concludes with a set of references, a bibliography and a source of further information.
With the decline of hardwood saw milling in the UK there has been a considerable loss of knowledge and skill in the whole realm of hardwood conversion and drying. The new small-scale producers, many of them coming into business through the support of woodland initiatives, will find this guide invaluable.
This guide should be in every architect’s and interior designer’s library and on the desk of every UK hardwood producer.
Copies of this guide are available free of charge from: Forestry Commission Publications Tel: 0870 121 4180. It is also available as a PDF file which can be downloaded from: www.forestry.gov.uk/hardwoods
Review by Roger G Venables
Elm table with spalted timber used for the drawer front (Woodschool Ltd)