The new version of EN 14018-1 “Timber structures – Strength graded structural timber with rectangular cross section. Part 1: General requirements” has now been published by the British Standards Institution.
This is the head standard that specifies requirements for strength graded structural timber (with cross-sectional dimensions complying with EN 336).
(Note: this standard still needs to be cited in the OJEU before it becomes a ‘proper’ harmonised standard. Edit: 13 December 2016. This still has not happened. There is very brief*, but not understandable, feedback from the European Commission via CEN – but a better explanation of the required work is still needed)
This new issue also means withdrawal of part 4 (EN 14081-4:2009), which contains some grading machine settings. This standard had not been updated for a long time and it was an impossible task to revise the standard quickly enough to incorporate new machine grading settings as fast as they were approved. There are also now so now so many tables of settings they could not possibly be fitted into a standard. Instead, settings that are accepted by CEN/TC124 (via TG1) will be documented in “Approved Grading Reports (AGR)”. It is envisaged that producers will obtain these settings through the grading machine manufacturers, while Notified Bodies will obtain them through Sector Group 18’s website.
Other modifications include:
- Updates to Clause 6 and Annex ZA to adapt to the Construction Products Regulations (CE marking etc)
- New clauses on Fire Resistance, release of dangerous substances, geometrical data and environmental issues
- Improvement of some definitions
The improvement of definitions includes some changes of meaning (compared to what many previously understood). Chief among these is the clarification that “dry graded timber” is timber for which the grading is completed at a moisture content of 20% or less. Completed means the check for fissures and distortion – the rest of the grading could have been done at higher moisture content, provided that moisture content was taken into account during grading. There is no direct correspondence with service classes (more here).
For the UK the biggest change is in what is now permitted in terms of marking the timber. BS EN 14801-1 has text in the National Forward and National Annex to clarify the official UK position.
“The UK committee took an active part in developing this edition of EN 14081-1. They do however disagree with what has been included in this standard for strength graded timber with only ‘package marking’.
National Annex NA of this document confirms the committee’s position on strength graded timber marked according to Method B (package marking). It also provides guidance on the CE marking and documentation requirements set out by this standard and the Construction Products Regulation (EU) No 305/2011.”
For more information on marking (what is now covered in the NA), see our previous blog post on grade stamps.
* the feedback from the European Commission, via CEN, as of the date of the CEN TC124 WG2 meeting (13 December 2016) is “AVCP system shall not be mentioned in the standard; additional values for class 4 for “penetration” (table 1); Table 2: classes indicating “no requirements” or “to be reported” (added value?)