The British Woodworking Federation (BWF) plays a key role in shaping national and European timber standards through its leadership of BSI Technical Committee B/543. In this blog, BWF Technical Director Kevin Underwood, outlines the key standards affecting joinery manufacturers, their impact on the industry, and how professionals in the industry can contribute to updating and refining these essential regulations.
The BWF chairs the BSI Technical Committee B/543, which is responsible for national standards for round and sawn timber. It also provides the UK’s input to the European Technical Committee CEN/TC 175. Around half of the standards under B/543’s remit are used by joinery manufacturers, covering timber applications in windows, doors, staircases, and flooring. Other standards relate to wood as a raw material, including both sawlogs and sawn timber.
Some of the key standards covered by B/543 include:
BS EN 942 superseded BS 1186-1:1991 and sets out how to determine the quality class of a timber component. These are known as “J” classes, ranging from J2 (highest quality) to J50. The classification considers factors such as knot size and distribution, as well as other features like splits, resin pockets, and grain slope. There is no direct correlation between J classes and traditional timber grades (e.g., “unsorted” or “fifths”), as sawn timber can be selected or defect-cut to achieve a higher J class.
BS EN 942 also includes a National Annex, which retains tables from BS 1186-1 describing various hardwood and softwood species and their suitability for joinery. For each species, the table provides information on:
Updating Standards and Committee Membership
Many of these standards, while essential for joinery manufacturers, require review and updates. To achieve this effectively, B/543 relies on the expertise of a broad range of committee members. BSI Technical Committees welcome new members, who may be individuals or representatives of a company or nominating body.
Committee members should have:
How to Join B/543
To apply for committee membership: