Some of TRADA’s research projects focus on technical issues which enhance markets for timber while others tackle more overtly commercial concerns. The projects are devised and validated by the industry through a committee of TRADA members and are carried out by TRADA Technology.

Funding comes partly from membership subscriptions and also from UK government sponsorship or EU sources. Other organisations within the industry also participate, together with academic institutions and commercial partners who contribute in cash or in kind. The net result can be that every pound of membership money spent on research, delivers up to £4 of benefit.

Improving competitiveness

Increasing the competitiveness of the UK construction industry and its supply chains has been a government target.

This includes the competitiveness of British grown structural timber. A TRADA study reviewed the current route to market of UK structural timber and how other countries optimise their timber resources.

A key message coming out of the project was that the construction industry seeks solutions to problems – delivery of a roof, a floor or a whole building – rather than supply of individual material components. Barriers identified to UK timber competitiveness included a lack of understanding, availability, quality and poor technical support for practitioners. The findings were disseminated through workshops for timber and construction groups.

Limit states design

Until recently, structural timber design in the UK mainly followed permissible stress principles – the only important structural material still using this format rather than limit states principles. This will change over the next few years with the publication of Eurocode 5 as a definitive EN code. Limit states define conditions beyond which a structure no longer satisfies its design performance requirements.

The ‘demystifying’ project had two objectives. To generate a critical mass of informed professional knowledge about modern timber design and to improve awareness of British timber products. Over 1,200 civil and structural engineers attended workshop teach-ins. The results were fed back to the British Standards committee for input into the definitive version of Eurocode 5.

The transition from British to European standards (ENs) under the Construction Products Directive raises issues and conflicts which need to be addressed to ensure a relevant and workable system for the UK timber and construction industries. In particular, the mix of retained British standards and new European standards leaves open the possibility of real problems with cross-referencing and conflicting requirements.

The task undertaken by TRADA Technology was, firstly, to identify all relevant BS ENs, the BSs they replace and those BSs being retained. This produced more than 500 documents under the jurisdiction of nine different BSI technical committees. The cross-referencing between the standards and the implications of changes was then examined under sector categories – wood based panels, non-structural timber, preservation, coatings, structural timber and adhesives. A set of 47 key standards documents was identified, with detailed recommendations for changes to the cross references.

Wood based panels

Improvements in engineering design values for structural wood based panels could be achieved by better test methods, ultimately leading to more efficient and economic structures. The greatest scope for exploiting shear properties is in thin webbed beams, portal frames and stressed skin panels.

Existing test procedures for determining shear properties of wood based panels are provisional and appear in an annex to EN 789. Prior research indicated that these test methods may significantly underestimate shear modulus and that in panel shear, the correct failure mode is often not obtained.

A European research project, co-ordinated by TRADA Technology, used mathematical modelling and physical testing to develop a better understanding of test methods and how these relate to the design and behaviour of components and structures.

Distribution and storage are significant elements in the cost and environmental impact of timber products which could be considerably reduced by better supply chain management. TRADA’s study of UK supply chains encompasses softwood, hardwood, panel products, wood based components, by-products and residues. Case studies enable comparisons to be made with other industries. Best practice benchmarks can then be established and recommendations made.

New age flitch beams

Flitch beams – a thin steel plate sandwiched between timber beams to form a composite section – have been in use since the 1800s. The ‘new age’ flitch is a composite engineered timber and steel product using UK grown softwood with shot-fired dowels to create the shear transfer between the materials. The research project is in four stages – product verification and determining what users want, prototype testing, system development and technical support and, finally, disseminating the information.

The majority of recent or emerging technologies for improving structural timber efficiency rely on some form of adhesive. Examples include composite materials, structural connections, localised reinforcement and repair and renovation. Only a very few adhesives are recognised in current structural timber design codes and these are for close-tolerance joints. Gap-filling adhesives are not covered nor is general design guidance available. As a result, the exploitation of such technology has been limited to innovative specialist manufacturers.

The project aims to open up opportunities by developing a performance classification, benchmarked against market leading types, for specific applications. Final output will include an IT-based designers’ information package to provide the links between the performance classification system and design codes.

Key performance indicators

Key Performance Indicators (KPIs) have been developed for the construction industry by the former Department of the Environment, Transport and the Regions through the Movement for Innovation (M4i), the Construction Industry Board and the Construction Best Practice Programme.

They are used to present critical business issues and create industry standards by which managers can measure performance within their organisations and stimulate improvement. Development of the pan-construction KPIs showed that people respond more enthusiastically to information related specifically to their own business sector.

The TRADA project will generate a set of KPIs specific to the timber construction supply chain by identifying critical issues, establishing a mechanism and process by which data within the KPIs is collected, collated and analysed and then disseminating the first set of specific timber KPIs.

Statistics

A pilot study in 1996 concluded that statistical information for the timber industries was slow to appear, and was often incomplete or irrelevant and did not address user needs. One of the reasons is the cumbersome, often deficient system for coding timber products in international trade used to collect customs tariffs as well as to generate statistics.

The TRADA project was to improve the scope, currency and quality of statistical and market information from existing providers and also to develop new channels where current data are insufficient. Specifically, the industry’s needs were canvassed through extensive consultation.

Proposals have been submitted to the European woodworking body, CEI Bois, for consideration by Eurostat and customs committees. If adopted, they will impact not only on customs tariffs but, even more importantly, on the business process by making it easier to see trends and take informed management decisions.