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 942:2007 – Timber in joinery: General requirements
- BS EN 14220:2006 – Timber and wood-based materials in external windows, door leaves, and doorframes: Requirements and specifications
- BS EN 14221:2006 – Timber and wood-based materials in internal windows, door leaves, and doorframes: Requirements and specifications
- BS EN 13307-1:2006 – Timber blanks and semi-finished profiles for non-structural uses: Requirements
- DD CEN/TS 13307-2:2009 – Laminated and finger-jointed timber blanks and semi-finished profiles for non-structural uses: Production control
- BS 8605-1:2014 – External timber cladding: Method of specifying
- BS 1186-2:1988 – Timber for and workmanship in joinery: Part 2 – Specification for workmanship
- BS 1186-3:1990 – Timber for and workmanship in joinery: Specification for wood trim and its fixing
BS EN 942 superseded BS 1186-1:1991 and sets out how to determine the quality class of a timber component.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:
- Characteristics – e.g., colour, texture, interlocked grain, potential to stain masonry or metal discolouration risks
- Average density at 15% moisture content
- Workability
- Dimensional movement due to moisture changes
- Suitability for internal and external joinery
- Need for preservative treatment
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:
- Relevant knowledge and experience
- Strong communication and influencing skills
- The ability to work towards a shared goal and build consensus
- Computer literacy (emailing, online collaboration, video meetings, word processing, and spreadsheets)
How to Join B/543
To apply for committee membership:
- New applicants should complete BSI’s online Standard Makers Application Form. https://uk.surveymonkey.com/r/BSI-Standards-Maker-App
- Company or nominating body representatives must arrange for an authorised individual to email BSI’s Committee Service Centre confirming their nomination.
- Membership approval is at BSI’s discretion. BSI aims to ensure committees reflect the necessary technical expertise, fairly represent all affected interests, and uphold its commitment to diversity and inclusion.
