It’s a Question of Standards
For many years, wood and wood products used in the construction industry in the UK have been covered by a range of British Standards and more recently, European Standards. These provide designers, specifiers, buyers and users with assurance of fitness for purpose and performance.
In 1985 the European Commission introduced a number of Directives aimed at technical harmonisation. The Construction Products Directive (CPD) has since been transposed into UK law as the Construction Products Regulations. The CPD differs from some other Directives in that it applies standards to the finished works into which construction products are used, rather than applying them direct to the products themselves.
What is CE marking?
The CPD introduced the concept of CE marking, which demonstrates conformance with the Directive. In all of the Member States, except UK, Ireland, Sweden and Portugal, the only way to show compliance is by applying the CE mark, (CE, from the French, Conformité Européan). In the in the four ‘opt out’ countries, applying the CE mark is not mandatory, but compliance with the CPD is.
The CE mark is intended to promote the free movement of products throughout the EU, by showing that essential health and safety requirements have been met. It is not a statement of quality as such; it is simply a ‘fitness for purpose’ mark.
What is the function of a CE mark?
The CE mark makes a claim that the product bearing the mark has been legally placed on the market within the EU, as required by the CPD on the grounds that;
The composite claim is shortened in the CPD to the focus of enabling the “works” in which the products are used to comply with the Directive’s Essential Requirements. These may include mechanical resistance ands stability, safety in case of fire, hygiene, health and the environment, safety in use, protection against noise and energy economy and heat retention.
Under the regulatory procedure, the EC generally issues a mandate for an appropriate form of Technical Specification. This will contain conformance criteria reflecting the Essential Requirements deemed by the Commission to be relevant to the product group in question. The possible types of Technical Specification may include; Harmonised Standards, European Technical Approvals or possibly, national technical specifications.
The conformity of wood based panels with the regulatory requirements rests almost entirely on the criteria contained in the mandated Harmonised Standard, EN 13986 ‘Wood based panels for use in construction – Characteristics, evaluation of conformity and marking’.
The Harmonised Standard (hEN) encapsulates the requirements of around 100 individual standards containing specifications, performance criteria and test methods applicable to particleboards (chipboard), fibreboards (including MDF), OSB and plywood and which covers performance characteristics that relate to the full range of essential requirements, as well as durability. This is the document according to which CE marking will be carried out for the great majority of wood based panels.
The hEN specifies all the conformity elements that have to be satisfied, including marking requirements and lists the appropriate systems of attestation of conformity – the required system and degree of involvement of a Notified Body depending on whether the panel products is to be used as a structural or a non-structural element and on the reaction to fire class that the product belongs.
Who applies the mark?
It is for the manufacturer, or his agent to apply the CE Mark on the product itself, on a label attached to it, or on its packaging, or on the accompanying commercial documents. There is a hierarchy of preference for location of the CE mark. Wherever possible, the CE mark should be applied to the product itself. If this is not possible, other options are available. The CE mark should be affixed visibly, legibly and indelibly. The CE mark must be applied before the product is placed on the market.
What does the CE mark tell me?
The CE mark is only the basic symbol, but accompanying information consists first and foremost of;
The Construction Products Regulations make it an offence to supply any construction product (other than a minor part product) not conforming with the requirement that it ‘shall have such characteristics that the works in which it is to be incorporated, assembled, applied or installed can, if properly designed and built, satisfy the essential requirements when, where and to the extent that such works are subject to regulations containing such requirements”’.
The enforcement authorities are the Trading Standards Departments of local authorities in Great Britain, environmental health authorities in Northern Ireland and the Department of Trade and Industry.
Wood based panel products and CE marking.
Amongst wood products used in the construction industry, wood based panel products are now covered by CE marking, following the publication of a harmonised European Standard, EN 13986, which has been the first harmonised Standard to be published for timber products. CE marking has been available on a voluntary basis from March 2003, with compulsory CE marking in most Member States from March 2004.
CE marked plywood – structural and non-structural applications
It should be noted that that the CPD applies to both structural and non-structural wood based panels. Therefore, the fact that a plywood carries a CE Mark does not necessarily mean that it is suitable for structural applications. Two questions must be answered; has the plywood been independently type tested for structural use in accordance with the procedures given in EN 13986 and which European Notified Body has approved the structural type testing and is providing the independent third-party quality assurance?
Unfortunately, the CE marking of structural and non-structural plywood is not very different; however, the CE Mark for structural plywood must always show a reference to identify the Notified Body.
It should be remembered that BS 5268-2 ‘Structural use of timber - Code of Practice for permissible stress design, materials and workmanship’, is a design code and will therefore remain the primary design document until it is eventually replaced by Eurocode 5 in a few years time. The plywood products listed for structural applications in BS 5268-2 are not exempt form CE marking and most have already achieved a CE mark because they have always had the two main criteria of independent structural type testing and independent third party quality assurance.
What about CE marking of other wood products used in construction?
As we have seen, publication of a harmonised European Standard is a prerequisite for CE marking.
Development of the harmonised European Standard for structural timber is proceeding. EN14081 will have four parts and completion of the fourth part is awaited. Once this is finished and the entire draft Standard is approved, it can be published, thereby opening the way for CE marking of structural timber, alongside the well established British Standard and European Standard marking.
Harmonised Standards for roof trusses, laminated timber beams, doors and windows, Laminated Veneer Lumber (LVL) and Structural Insulated Panels are also in preparation.
A number of timber and timber related products are currently covered by European Technical Approval Guidelines (ETAG’s) and may carry CE marks. These include timber frame components, prefabricated stairs and I-beams.
Be assured …
Despite the introduction of CE marking for wood based panel products, it is the case that wood and wood products used in construction, and indeed a wide range of other end uses too, have been covered by British Standards for many years and now by European Standards as well. These form the basis of specifications and provide safeguards for specifiers, buyers and users.
For further information
For further information contact the STTA office, any STTA Member Company, or the following organisations,
Wood Panel Industries Federation - www.wpif.org.uk
Timber Trade Federation - www.ttf.co.uk
TRADA - www.asktrada.co.uk