Trussed Rafters

The roots of BM TRADA Certification Limited (BM TRADA) go back to TRADA (the Timber Research and Development Association) and the company now forms part of the TTL Chiltern Group of Companies.

Set up in 1974 to provide product certification for the timber industry, BM TRADA now operates across a wide range of industries in both the public and private sectors world-wide, offering quality, environment, personnel and product certification services to a vast and variety of organisations.

One of BM TRADA’s schemes accredited by UKAS, the United Kingdom authority for certification bodies, is the TRUSSED RAFTER SCHEME.

This is operated as a Product Certification scheme and meets the System Certification requirements of ISO 9001:2000 “Quality Systems” and the technical requirements of the relevant sections of BS 5268: Part 2 “Structural Use of Timber - Code of Practice for permissible stress design, materials and workmanship” and BS 5268: Part 3 “Structural use of timber - Code of Practice for trussed rafter roofs”. 

Companies who wish to join the Trussed Rafter Association must now either have an approved ISO 9001:2000 system in place or be a member of BM TRADA’s Trussed Rafter Scheme. 

The scheme draws its membership from across the Trussed Rafter Industry.  Membership is gained through an initial factory inspection where the company’s management organisations and documentation and quality systems are reviewed.  Although the trussed rafter designs themselves are not checked, their source is important and this must either be one of the recognised system licensors or a suitably qualified engineer.

The manufacturing requirements are those laid down in BS 5268: Part 3 and in BS EN 14250:2004 “Timber structures: Product requirements for prefabricated structural members assembled with punched metal plate fasteners” and cover timber quality and size, moisture content, joint gaps and plate pressing and overall dimensional tolerances.  The company’s methods with regard to preservation treatment, storage and transport and, of course, the finished trussed rafters themselves are also scrutinised.

The scheme requires that the company nominates certain staff to be responsible for the control of its manufacturing quality and there is  a manager will overall responsibility for quality, an inspector to carry out the required weekly quality control monitoring checks and a qualified grader, where appropriate, to verify the grade of timber used.

Scheme members are licensed to use the mark shown below.


 

BM TRADA’s supervision of the scheme normally takes the form of two surveillance visits per year to ensure that the quality system agreed at the initial visit is being operated satisfactorily, that the quality control monitoring checks are being carried out and their results appraised, and also to provide an independent detailed check on a sample of the company’s production.

All trussed rafters should be marked or labelled with:

• the name of the manufacturer
• the species and strength grades or strength classes of timber
• a confirmation that the truss rafter has been designed in accordance with recommendations of BS 5268: Part 3. / BS EN 14250.

In addition, members of BM TRADA’s Trussed Rafter Scheme can mark their products with the
BM TRADA Q-Mark.

The BM TRADA Q-Mark

The Q-Mark is readily identified as a market leader in the certification of timber related products together with a widening range of other construction materials.  Once a company has had its products approved under the scope of Q-Mark, it is permitted to use the logo on both literature and products.

View all the members of the Trussed Rafter Scheme
View all the provisional members of the Trussed Rafter Scheme

For further information please call our head office on 01494 569700 or email enquiries@bmtrada.com. Whatever business you are in, we will be happy to advise you on the most cost-effective route to registration.