While there are many types and grades of plywood available in the UK, imported from around the world only certain types and grades from certain countries, are deemed suitable for structural use here.
The use of appropriate plywood for structural applications has been an issue for some time, but there is now growing consensus on the need to educate specifiers, suppliers and buyers and stamp out use of unapproved material.
President of the Scottish Timber Trade Association (STTA), Bruce Muirhead said: ‘It is vital that the timber trade recognise the importance of this issue. If the wrong grade of material is supplied and subsequently suffers structural failure, timber as a whole loses market share. Ignorance of end use is no excuse: STTA members, as suppliers, share responsibility with specifiers and purchasers to check end use so that the correct grade can be supplied.’
He adds: ‘There are many applications where the use of less costly non-structural plywood is adequate. The responsible supplier must, however, ensure that the customer is aware of the right grade for the job and does not choose just on price. Where non-structural plywood is supplied, documentation from the supplier must make this clear.’
‘We want to see responsibility for the use of appropriate structrual plywood taken by all the sectors: designers, specifiers, importers, merchants,buyers and site staff.’
Choosing the right plywood for structural applications is easier than many people think. Here are some pointers to ensure that the correct type and grade are used.
Plywood for structural use in the UK is described in BS 5268: Part 2. Such plywood is made under the auspices of independent third party quality assurance, guaranteeing physical characteristics and properties. If it is not in BS 5268: Part 2, or does not have a British Board of Agrément certificate, it is not fit for structural use in the UK.
BS 5268: Part 2 also requires that every sheet of plywood recommended for structural applications is clearly marked with the appropriate structural plywood grade mark. Examples of these grade marks are given in BS 5268: Part 2. If a sheet of plywood does not have the right mark, it is not suitable for structural use in the UK.
BS 5268: Part 2 lists only certain types and grades of plywood produced in Canada, Finland, Sweden and the US as appropriate for structural use in the UK. Only certain specified grades from each of these countries are permitted for structural use and the correct grade must be specified for each application. BS 5268: Part 2 also provides essential design guidance and design data for specified plywood types and grades.
It is also possible for products to demonstrate that they meet the requirements of Building Standards through product conformity certification from the BBA.
So the situation for suppliers and specifiers is straightforward: anyone who uses any of the plywood products listed in BS 5268: Part 2 can be confident that the product will, without question, meet current requirements for structural plywood, as long as the correct thickness is specified and used. Similarly, with the same provisos, plywood products with BBA certification can be specified and supplied with confidence.
If building control officers find that non-BS 5268-compliant material has been used in a structural application, they can order its removal or demand detailed proof that it is of an equivalent standard. If non-compliant plywood is used in this way, is not initially discovered and then fails, there may be charges of negligence.
The STTA’s message is: ‘If in doubt, ask’ and advice is available from various sources – the Timber Trade Federation; the STTA; TRADA Technology Ltd; APA – the Engineered Wood Association; and CANPLY. In addition, the National Panel Products Division has circulated a list of types of plywood listed in BS 5268: Part 2 as being for structural applications or which have the necessary BBA certification.
The NPPD is producing a code of practice which all TTF members who deal in panel products will be required to adopt, comply with and display. The aim is to ensure that specifiers and users of structural plywood can buy with confidence from TTF (and STTA) members who, under the code, commit to selling panel products with precise descriptions and appropriate advice.
