WPA Benchmark TW scheme

What is WPA Wood Protection Association?

The WPA is a not for profit UK trade association focused on the development and promotion of wood protection technology to support the use of wood as a cost effective, sustainable and low environmental impact construction material.

The WPA acts as a technical advisor to British and European Standards setters on wood preservation, modified wood and the fire protection of wood.

What is WPA Benchmark TW scheme?

The WPA Benchmark Approved (TW) Scheme relates specifically to the durability of wood and wood based materials pre-treated by an industrial process.

Treated wood product lines for which the production process has been subject to audit and for which the required penetration and retention of preservative has been assured by direct testing or by safe relationship (indirect) testing*. Approved Products must comply with the requirements of BS8417 / WPA Code of Practice: Industrial Wood Preservation and will normally be defined by end use/Use Class, species and service life as a minimum. The scope of Products approved will be recorded on a company’s Benchmark accreditation certificate and should be clearly stated in/on company marketing materials, online or in paper form.

(*as defined in the WPA Code of Practice)

Whilst BS 8417 recommends the levels of preservative penetration and retention it does not provide guidance on how these critical minimum requirements are to be achieved – it points to the WPA Code of Practice: Industrial Wood Preservation to provide guidance in achieving this performance benchmark.

The WPA Benchmark Scheme therefore operates on the principle that wood consistently treated in accordance with the WPA Code of Practice is a durable material which will exhibit the minimum penetration and retention requirements for the relevant end use and service life.