The construction industry is facing one of the most significant changes for a decade as CE Marking of construction products becomes mandatory in all Member States throughout the European Union and the European Economic Area.
CE Marking for all construction products, covered by a harmonised European standard or conforming to a European Technical Assessment became mandatory on 1 July 2013. For fabricated structural steelwork, CE Marking became mandatory on 1 July 2014. This represents a major development for engineers, contractors and steelwork specialists and it demands careful attention to the new obligations imposed.
This article highlights how the steel construction sector has been working behind the scenes towards achieving CE Marking. Perhaps more importantly, it spells out in detail what it will mean for the rest of the construction sector and what you need to do to comply with the Construction Products Regulation, which is the legal basis for the new regime.
|An introduction to CE Marking
with contributions from:
CE Marking (originally Conformité Européenne) demonstrates compliance with the appropriate manufacturing standard for a product. As a symbol, it will be familiar as it has been a requirement for many years on products sold in the European Union such as toys and electrical goods.
Under the Construction Products Regulation (CPR), new legal obligations have been placed on manufacturers, distributors and importers of construction products used within the EU to CE Mark their products where they are covered by either a harmonised standard or European Technical Assessment (ETA). This applies not only to constituent products (such as steel beams, bolts etc) but also to fabricated elements and systems made from CE Marked products. In the UK, penalties for non-compliance include suspension notices, prohibition notices, notices to warn, and application for forfeiture. For certain offences the penalties may include a fine, imprisonment or both.
The CPR describes the legal obligations it places on the construction supply chain in terms of ‘manufacturers’, ‘distributors’ and ‘importers’. However, the construction supply chain in the UK would normally be described in terms of clients, designers, specifiers, contractors and specialist subcontractors. The purpose of this article is to provide some guidance to the UK supply chain on the implications of the CPR on steel construction.
The requirements of the CPR and CE Marking apply to construction products used on a project irrespective of whether that project was designed to National Standards (e.g. BS 5950) or to the Eurocodes .
CE Marking of products
Under the CPR, all products used in construction must now have CE Marking to demonstrate compliance where either a harmonised standard or a European Technical Assessment (ETA) is in force. All mainstream construction products are covered by harmonised standards and must therefore be CE Marked.
For fabricated structural steelwork, engineers, contractors and steelwork contractors should have amended their specifications accordingly to ensure only CE Marked products are used on their projects.
This has not caused any disruption in the supply of material as manufacturers, such as Tata Steel with their Advance® section range and Celsius® 355 NH and Hybox® 355 structural hollow sections, had been CE Marking their products for a number of years in anticipation of the CPR requirement. A 'Declaration of Performance' for each CE Marked product from Tata Steel is available here to view or download.
Product standards for CE Marking
Mandatory for products
- Non-preloaded structural bolting assemblies – BS EN 15048-1
- High strength structural bolting assemblies for preloading – BS EN 14399-1
Mandatory for fabricated steelwork
- A full list of harmonised standards can be found on the European Commission, Enterprise and Industry, Nando website.
- A full list of ETAs can be found on the European Organisation for Technical Approvals (EOTA) website.
CE Marking of fabricated structural steelwork
The harmonised standard covering fabricated structural steelwork is BS EN 1090: Execution of steel structures and aluminium structures.
Part 1 of the standard is the Requirements for Conformity Assessment of Structural Components. It describes how manufacturers can demonstrate that the components they produce meet the declared performance characteristics (the structural characteristics which make them fit for their particular use and function).
Part 2 is the Technical Requirements for Steel Structures. It specifies the requirements for the execution of steel structures to ensure adequate levels of mechanical resistance and stability, serviceability and durability. It determines the performance characteristics for components that the manufacturer must achieve and declare through the requirements of Part 1.
The BCSA made CE Marking compliance a condition of membership of the Association from 1 July 2014, so selection of any BCSA Member company will guarantee that the steelwork contractor will have the necessary certification to comply with the CPR requirements. Clients and main contractors will therefore have confidence in the complete supply chain for steel construction from manufacture of the steel sections through distribution to fabrication and erection on site.
Contracts for fabricated structural steelwork to be delivered to site on or after 1 July 2014 should include the following specifications, which incorporate the obligations of BS EN 1090-1 and BS EN 1090-2 on the steelwork contractor:
- National Structural Steelwork Specification (NSSS) for Building Construction 5th Edition CE Marking Version
- Specification for Highway Works, Series 1800, Structural Steelwork
- the works as a whole
- an individual component
- a detail of a component
The engineer is responsible for specifying the Execution Class for the structure, the components and the details. In some cases the Execution Class for the structure, the components and the details will be the same while in other cases the Execution Class for the components and the details may be different to that for the whole structure.
The procedure for determining the Execution Class is a straightforward four step process:
- Determine the Consequence Class
- Define the Service Category
- Define the Production Category
- Derive the Execution Class
Whilst each building needs to be considered on its own merits, Execution Class 2 (EXC2) will be appropriate for the majority of buildings constructed in the UK. If the Execution Class is not specified on a project, Clause 4.1.2 of BS EN 1090-2 states that EXC2 shall apply.
It should also be noted that the NSSS for Building Construction 5th Edition CE Marking Version has been written for the steelwork contractor to deliver the requirements of EXC2. This is now the only valid version of the NSSS.
Step 1 - Determine the Consequence Class
The purpose of categorising the Consequence Class is to ensure that buildings (and other structures) are constructed with the appropriate level of quality control within the fabrication process. Consequence Classes are derived on the basis of building type, building height (number of storeys), floor plan area per storey (for retail) and occupancy. A structure, or a part of it, could also contain components with different Consequence Classes.
BS EN 1990 gives guidelines for the choice of Consequence Class in Table B1 (below).
|Consequence Class||Description||Examples of buildings and civil engineering works|
|CC3||High consequence for loss of human life|
or economic, social or environmental consequences very great
|Grandstands, public buildings where consequences of failure are high (e.g. a concert hall)|
|CC2||Medium consequence for loss of human life;|
economic, social or environmental consequences considerable
|Residential and office buildings, public buildings where consequences of failure are medium (e.g. an office building)|
|CC1||Low consequence for loss of human life|
and economic, social or environmental consequences small or negligible
|Agricultural buildings where people do not normally enter (e.g. storage buildings), greenhouses|
Table A.1 of BS EN 1991-1-7 (below) gives examples of categorisation of building type and occupancy according to Consequence Classes that assist with the implementation of Annex B of BS EN 1990.
|Consequence Class||Example of categorisation of building type and occupancy|
|1||Single occupancy house not exceeding 4 storeys. |
Lower Risk Group
|5 storey single occupancy houses. |
Hotels not exceeding 4 storeys.
Upper Risk Group
| Hotels, flats, apartments and other residential buildings greater than 4 storeys but not exceeding 15 storeys. |
Educational buildings greater than a single storey but not exceeding 15 storeys.
|3|| All buildings defined above as Class 2 Lower and Upper Consequence Class that exceed the limits on area and number of storeys. |
All buildings to which members of the public are admitted in significant numbers.
- For buildings intended for more than one type of use the ‘Consequence Class’ should be that relating to the most onerous type.
- In determining the number of storeys, basement storeys may be excluded provided such basement storeys fulfil the requirements of ‘Consequences Class 2b Upper Risk Group’
- UK Building Regulations Approved Document A contains a similar table to A.1 of EN 1991-1-7 which may also be used to determine the Consequence Class.
SCI Guide P391 provides guidance on classification of mixed-use buildings and buildings with basements (see below).
(Note: as classification classes are also used to determine the robustness strategy for a building, some of the guidance is dependent on the robustness strategy adopted, particularly where basements are present.)
|2 storeys of flats over one storey of retailing premises. This case should be considered as 3 storeys of retailing premises. Therefore, apply Class 2a to the whole building, or apply Class 2b to the whole building if floor area of retailing premises is 1000m2 or more (per storey).|
|2 storeys of flats over 2 storeys of retailing premises. This case should be taken as 4 storeys of retailing premises. Therefore, apply Class 2b to the whole building.|
|4 storeys of flats adjacent to 5 storeys of offices. Class 2b should be applied to the 5 storey office area and extending to a suitable structural discontinuity in the 4 storey residential area and Class 2a should be applied to the remaining 4 storey residential area.|
|In determining the number of storeys for classification, basement storeys may be excluded if they fulfil the robustness requirements of Class 2b buildings. Otherwise, the basement storeys must be included in determining the number of storeys for building classification. The basement can be for habitable accommodation or parking.|
Step 2 - Define the Service Category
Service categories are the method used in BS EN 1090-2 to consider the risk from the actions to which the structure and its parts are likely to be exposed to during erection and use, such as fatigue and likelihood of seismic actions. They also consider the stress levels in the components in relation to their resistance.
Service categories are determined from Table B.1 of BS EN 1090-2 (see below), but for most buildings in the UK, SC1 will be appropriate.
- DCL, DCM, DCH: ductility classes according to BS EN 1998-1
- For classification of fatigue actions from cranes, see BS EN 1991-3 and BS EN 13001-1.
Step 3 - Define the Production Category
Production categories are the method used in BS EN 1090-2 to consider the risk from the complexity of the fabrication of the structure and its components, e.g. application of particular techniques, procedures or controls.
Production categories are determined from Table B.2 of BS EN 1090-2 (see below) and it should be noted that a structure or part of a structure may contain components or structural details that belong to different production categories.
However, in all cases, the Execution Class is not sensitive to the Production Category selected.
Step 4 - Derive the Execution Class
Having determined the Consequence Class, Service Category and Production Category for a building, the required Execution Class is derived simply from Table B.3 of BS EN 1090-2 (see below).
|a EXC4 should be applied to special structures or structures with extreme consequences of a structural failure as required by national provisions|
Annex B of BS EN 1090-2 is classed as ‘informative’. Therefore the approach described is not mandatory and the engineer can base the selection of Execution Class on experience provided they can support their decision.
For the majority of buildings constructed in the UK, EXC2 will be the appropriate requirement. Where no Execution Class is specified, Clause 4.1.2 of BS EN 1090-2 states that EXC2 shall apply.
The engineer should always derive the Execution Class based on the design parameters appropriate to each project. The requirements to each Execution Class are listed in Table A3 of BS EN 1090-2 and can be reviewed by the engineer if desired.
However, the engineer should avoid over-specification of the Execution Class wherever possible to avoid unnecessary costs being introduced. For example, EXC2 is the Execution Class derived for a project but the engineer requires full traceability (an EXC3 requirement) instead of the partial (or batch) traceability requirement of EXC2. Rather than specifying EXC3 on the basis of achieving this single Clause requirement, it is suggested that EXC2 is still specified but with the higher level of traceability added to the specification.
Steelwork contractor requirements for CE Marking
In order to be able to CE Mark the fabricated structural steelwork that they produce, steelwork contractors are required to declare performance to the System 2+ level of assessment (as described in Annex V of the CPR). This requires them to undertake:
- Initial type-testing of the product
- Factory Production Control (FPC), which will include
They must also be assessed by a notified body that will carry out:
- Initial inspection of the manufacturing plant
- Initial inspection of the FPC
- Continuous surveillance, assessment and approval of the FPC, which will typically include:
- an annual audit to ensure continued competence to the declared Execution Class (Table B.3 of BS EN 1090-1 sets out minimum levels for the routine surveillance intervals)
The notified body will then issue a FPC certificate and Welding Certificate identifying the Execution Class that the steelwork contractor has achieved.
Client and/or main contractor’s responsibility
In order to achieve this, the client or main contractor should appoint a steelwork contractor with an Execution Class equal to that required for the project, as determined by BS EN 1090-1. It should be noted that steelwork contractors with EXC3 capability can be used for EXC1, 2, & 3; and a steelwork contractor with EXC2 capability can only be used for EXC1 & 2.
The BCSA made CE Marking compliance a condition of membership of the Association from 1 July 2014, so selection of a BCSA Member company will guarantee that the steelwork contractor will have the necessary accreditation to comply with the CPR requirements.
The directories for buildings and bridgeworks on BCSA’s website include details of accredited certification levels achieved by each member. Clients and main contractors can use this to find steelwork contractors with an Execution Class equal to that required for their project.
Contract documentation should also be updated to incorporate CE Marked version of NSSS 5th Edition, which incorporates the obligations of BS EN 1090-1 and BS EN 1090-2 on the steelwork contractor.
It should be noted that if a non-EU steelwork contractor is used on a project, the CPR puts liability on clients and/or main contractors. In that instance, the party engaging the steelwork contractor would be classed as an importer under the CPR and must comply with ‘Obligations of Importers’ given in Article 13 of the regulations.
How to check compliance with the CPR and CE Marking
- Factory Production Control (FPC) Certificate – issued by a notified body
- Welding Certificate – issued by a notified body
- Declaration of Performance (DoP) – issued by the steelwork contractor
The client or main contractor engaging the steelwork contractor should NOW carry out due diligence before appointing any steelwork contractor who will be delivering fabricated structural steelwork to site. Likewise, insurers should complete a similar due diligence process before giving Professional Indemnity insurance to a steelwork contractor who wants to CE Mark their products.
As the BCSA has made CE Marking compliance a condition of membership, simply selecting a BCSA Member will ensure compliance with the regulations. The client, main contractor or insurer would not need to carry out due diligence of the steelwork contractor in this case since it has already been undertaken by the BCSA as part of their membership audit.
What to check – Factory Production Control and Welding Certificates
- Declared performance – ensure that the steelwork contractor meets or exceeds the Execution Class requirements for the project.
- Base materials – the steelwork contractor is covered for welding with material strength and subgrades up to and including those declared on the Welding Certificate. Ensure that these are consistent with the requirements of the project.
- Date of next surveillance – check that the certificate is still current and covers the period of the contract.
- Notified body number – check on the EU’s Nando website to ensure that it is a valid and current number associated with the notified body named on each certificate.
What to check – Declaration of Performance
The scope of the DoP to be issued by the steelwork contractor for each project is set out in Article 6 of the CPR, with a standard form included as Annex III. The standard form in Annex III covers all aspects of the CPR, whereas the example below suggests what would be appropriate to include when CE Marking fabricated structural steelwork along with some comments that might be helpful in interpreting the intent of the DoP standard form.
- Steelwork contractor’s unique DoP Certificate identification number.
- Steelwork contractor defined (may be omitted if not relevant).
- Brief description of use, which may include project name and location.
- Check that notified body and level of assessment declared is consistent with the FPC and Welding Certificates where appropriate.
- Steelwork Contractors are not required to declare performance against all of the performance characteristics in Table ZA.1 of BS EN 1090-1, but only those that are appropriate and for which they are responsible.
- ^ 1.00 1.01 1.02 1.03 1.04 1.05 1.06 1.07 1.08 1.09 1.10 1.11 1.12 1.13 1.14 1.15 Construction Products Regulation (EU) No. 305/2011 of the European Parliament and of the Council of 9 March 2011, Official Journal of the European Union L88/5 4.4.2011
- ^ BS 5950 Structural use of steelwork in building (Various Parts). BSI
- ^ 3.0 3.1 BS EN 10025-1: 2004, Hot rolled products of structural steels, Part 1: General technical delivery conditions, BSI
- ^ BS EN 10210-1: 2006, Hot finished structural hollow sections of non-alloy and fine grain structural steels. Part 1: Technical delivery requirements. BSI
- ^ BS EN 10219-1: 2006, Cold formed welded structural sections of non-alloy and fine grain steels. Part 1: Technical delivery requirements. BSI
- ^ BS EN 15048-1:2007, Non-preloaded structural bolting assemblies. General requirements, BSI
- ^ BS EN 14399-1:2005, High-strength structural bolting assemblies for preloading. General requirements, BSI
- ^ 8.0 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 BS EN 1090-1:2009+A1:2011 Execution of steel structures and aluminium structures. Requirements for conformity assessment of structural components. BSI
- ^ 9.00 9.01 9.02 9.03 9.04 9.05 9.06 9.07 9.08 9.09 9.10 9.11 9.12 BS EN 1090-2:2008+A1:2011 Execution of steel structures and aluminium structures Technical requirements for steel structures. BSI
- ^ Manual of Contract Documents for Highway Works (MCHW). Volume 1: Specification for Highway Works. Series 1800 Structural Steelwork. August 2014, TSO
- ^ 11.0 11.1 BS EN 1990: 2002. Eurocode: Basis of structural design. BSI
- ^ 12.0 12.1 BS EN 1991-1-7:2006. Eurocode 1: Actions on structures. General actions. Accidental actions. BSI
- ^ Approved Document A - Structure (2004 Edition incorporating 2010 and 2013 amendments)
- ^ BS EN 1998-1:2004 Eurocode 8. Design of structures for earthquake resistance. General rules, seismic actions and rules for buildings. BSI
- ^ BS EN 1991-3:2006 Eurocode 1. Actions on structures. Actions induced by cranes and machinery. BSI
- ^ BS EN 13001-1:2004+A1:2009 Cranes. General design . General principles and requirements. BSI
- Steel construction – CE Marking supplement, 2013
- Plates and profiling slabs, A guide to our wide range of products. 2013, Tata Steel
- Advance® sections, CE marked structural sections, Eurocode version. 2013, Tata Steel
- Celsius® 355 NH technical guide, Structural hollow sections. 2013, Tata Steel
- Hybox® 355 technical guide, Structural hollow sections. 2010, Tata Steel
- Advance Sections app for section property and member capacity information through iPhones, iPod and iPad, 2013, Tata Steel
- Declarations of Performance certificates for Tata Steel products
- National Structural Steelwork Specification (5th Edition, CE Marking Version), Publication No. 52/10, BCSA, 2010
- SCI P391 Structural Robustness of Steel Framed Buildings, 2011
- Steel construction products
- Steelwork specification
- Specification of bridge steelwork
- Steel manufacture
- Structural robustness