Members’ Directory and Buyers’ Guide 2014
Code of Conduct
BS EN 314 testing determines which end-use Service Class from BS EN 636 the plywood may be suitable for:
EN 636-1 dry EN 636-2 humid EN 636-3 exterior
Biological durability of veneer species will influence life expectancy of plywood, but at the present time this is not a production consideration. The decision of correct product rests with the designer who is advised to use the guidance in BS EN 335.
BS EN 13986 states that where formaldehyde-containing materials, particularly aminoplastic resins, have been added to the product as part of the production process, the product shall be tested and classified into one of two classes: E1 or E2.
The Standard requires the testing and declaration of formaldehyde emission class for all wood-based panels in construction. The only exception to the testing requirement is plywood using phenolic resin throughout, which is permitted to declare Class E1 without testing. Plywood comprising any other type of resin or mixed gluelines, for instance when additional face veneers are applied, must be tested or re-tested to determine its correct formaldehyde emission class.
Plywood – Structural Performance A 2+ Certificate of Conformity from a Notified Body simply implies a plywood has been manufactured in a factory production control environment capable of producing structural panels. It gives no indication of the load individual panels are capable of carrying and, on its own, does not demonstrate fitness for purpose nor suitability for approved structural use.
BS 5268, Part 2, gives Structural Performance data only for the specific types of plywood listed in the appropriate tables. The supplier, normally within the Initial Type Testing data, must provide Structural Performance data for all other plywood claiming structural status. Variation of resin mix or application of additional face veneers
would invalidate this testing. Claims that structural plywood is equivalent to those listed in BS 5268, Part 2, means simply that structural properties have been tested in a similar way. However, the supplier must still provide the actual third-party results of structural testing performed on their products.
Plywood – Face Quality
The CE marking system does not recognise the face quality terms in the withdrawn standard BS 6566, Part 6, such as ‘BB/CC’, and therefore using one of these terms does not automatically qualify as plywood for any performance classification. Furthermore, within the CE marking criteria, quality of veneers used internally or on the face is not a defined requirement. However, initial type testing of structural performance would require a definition of the quality of veneers used, even if this was only in terms of density.
Notwithstanding CE marking, Members may describe their products using the face quality terms in the withdrawn standard BS 6566, Part 6, if they so choose. However, panels which are fall-down grades should always be described as such to prevent mis-representation of the product.
The European standards describing face quality of plywood are BS EN 635, Part 2 for Hardwoods, and Part 3 for Softwoods.
Other Wood-Based Panels
Unlike plywood, most wood-based panel products for structural application have tightly defined technical classes which should provide all the information necessary to correctly specify the product. The appropriate standards are listed below, and the descriptions used throughout the supply chain should always define a specific technical class, rather than simply using the generic name of the product, eg OSB.
OSB Panels To Meet BS EN 300 OSB/2 OSB/3
load-bearing, dry load-bearing, humid OSB/4
www.ttf.co.uk heavy-duty load-bearing, humid 31
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