038 RCI 0717

RCI July 2017

CLADDING & SHEETING featured heavily in the CE marking process. The difference between the two standards is important and is explained below: EN 1090-1 EN 1090-1 is the Harmonised Standard (hEN) for structural steelwork and includes the list of Essential Characteristics that may be declared by the manufacturer, along with the all-important Annex ZA that gives rules for the CE mark itself. As a harmonised standard, EN 1090-1 has one simple aim: To set out the framework for CE marking by stating which properties may be declared and how they should be measured. It sets out requirements for Initial Type Testing (ITT) and Factory Production Control (FPC), but does not directly set requirements for performance. To ensure that a minimum level of performance (and hence safety) is achieved, EN 1090-1 refers repeatedly to EN 1090-2 on matters such as fabrication tolerances and welding. Simply, a manufacturer CE marking to EN 1090-1 declares that its products comply with EN 1090-2 regarding the Essential Characteristics, and produces a set of FPC procedures ensuring this compliance is achieved in practice. EN 1090-2 EN 1090-2 is the Execution Standard for structural steelwork and includes details on matters such as tolerances and welding. Although often associated with CE marking due to the many 038 JULY 2017 RCIMAG.COM cross references from EN 1090-1, compliance with this standard is independent from the CE marking process. It goes much further than the Essential Characteristics declared on the CE label (seemingly lost on many CE marking auditors). Compliance with EN 1090-2 is essential for safety, since the structural engineer’s design calculations are only valid if the steelwork is fabricated to tolerance and welded correctly – clearly stated in EN 1993. Since BS 5502-22 refers to EN 1993 for the steel design and EN 1993 refers to EN 1090-2 for tolerances and welding, it follows that any building that fails to comply with EN 1090-2 automatically fails to comply with BS 5502-22. Latest code updates All of the Eurocode documents have been reviewed and are in various stages of being revised, starting with EN 1990. Many of the changes currently being discussed, such as robustness and reliability analysis, will have little impact on agricultural buildings. However, there is talk of replacing the equations used to combine snow and wind loading, with possible consequences for design loads. The main parts of EN 1991 and EN 1993 are now at the Working Group stage, where teams of experts from across Europe review the comments received on the existing standards and attempt to address them. Project Teams have just started the process of undertaking detailed technical work that will eventually feed into the revised Eurocodes. As a general trend, there is a move to reduce the number of Nationally Determined Parameters (NDPs), i.e. the values and equations that may be specified by individual countries through their National Annexes. No major changes to wind and snow loading are expected, although increases in both cannot be ruled out. Similarly, changes to EN 1993 are unlikely to have a significant impact on the design of steel framed sheds, since the underlying physics has not changed. In both cases however, changes to the design methods or equations would require software updates. The Project Teams and Working Groups have been asked to consider ‘ease of use’ aiming to make the Eurocodes easier to follow and navigate. Perhaps more significantly for steel frame manufacturers, EN 1090-1 and EN 1090-2 are also being revised with potential consequences for CE marking. Changes are proposed relating to the bolting and welding of structural steel, including new guidance on the selection of weld inspection classes and the use of preloaded bolts. Guidance on the selection of the execution class has been removed from EN 1090-2 and may now be found in Annex C of EN 1993-1-1. Requirements for cold-formed steel members and sheeting are now in EN 1090-4. The changes proposed to EN 1090-1 are more fundamental in nature and could see the link broken between this standard and EN 1090-2. If this change is implemented, compliance with EN 1090-2 will no longer be mandatory for CE marking, although it will still be essential for building safety and for compliance with BS 5502-22. www.ridba.org.uk Leading manufacturer of PVC-U & PVC-UE roofline products Fascia • Soffit • Rainwater www.freefoam.com 01604 591110 marketing@freefoam.com Follow us on


RCI July 2017
To see the actual publication please follow the link above