The Wood Protection Association

5c Flemming Court, Castleford, West Yorkshire

WF10 5HW. United Kingdom

WOOD: designed by nature, protected by innovation

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© 2019 The Wood Protection Association

The WPA administer industry recognised quality schemes to further assure products and processes are fit for purpose.

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The WPA Benchmark Quality Approval schemes cover formulations, processes and products – providing valid independent assessment and verification.  

 

Available schemes cover: Flame RetardantsPreservative Treatments and Modified Wood. 

Flame Retardant (FR) Schemes

Three interlocking approval schemes cover every stage in the production and distribution of flame retardant wood based materials. In each scheme, assessments and audits are conducted by independent experts.

WPA Benchmark Approved Formulations (FR)

The WPA Benchmark Approved Formulation (FR) scheme provides independent verification of the efficacy of a flame retardant formulation. It must be applied or added to wood based materials by a factory controlled process monitored under a recognised quality assurance scheme.

 

The data to be supplied in support of an application is clearly defined in a Scheme Document and is submitted to the WPA for assessment by an independent Efficacy Panel. 

The assessment includes:

  • examination of fire test certificates and classification reports and; 

  • other characteristics that affect performance in service such as wood strength and smoke emission. 

WPA Benchmark Approved Treaters (FR)

The WPA Benchmark Approved Treater (FR) scheme for wood-based materials relates to the factory process used to apply FR formulations. 

 

Where a flame retardant is added during the manufacturing process for MDF, OSB or plywood then that process should be subject to factory production control (accredited by a notified body). The product should carry the CE mark and be accompanied by a valid Declaration of Performance when it leaves the factory.

 

Where the product is factory FR treated after manufacture (solid wood, some plywood) by a service treater, that company must also operate factory production controls which have been accredited by a notified body, alongside those of the company placing the product on the market, so as to maintain full traceability. 

 

  • Treaters certificated under this scheme must use a WPA Benchmark Approved Formulation (FR)

  • The scheme provides independent third-party auditing and verification that the WPA Benchmark Approved flame retardant has been correctly applied. 

WPA Benchmark Approved Distributors (FR)

The WPA Benchmark Approved Distributor (FR) scheme is for companies supplying and distributing flame retardant treated wood products which have been treated by a third party, accredited under the WPA Benchmark Approved Treater (FR) scheme and using a WPA Benchmark Approved Formulation (FR).

 

The Scheme provides independent third-party verification that such distributors can trace products back through their supply chain to verifiable fire test classification reports.​

 
 

WPA FR Build approved members

The FR Build scheme is operated by WPA for the Structural Timber Association (STA).

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It provides third-party certification of the factory process used to apply STA approved flame retardant on timbers used in the construction phase of a building.  This scheme does not confirm compliance of the chemical formulation used with STA performance requirements - that is the responsibility of the chemical manufacturer.  

Apply for Scheme Approval

If you are interested in submitting an application for a formulation, product or distribution service for any of the WPA Quality Schemes, Contact Us directly and ask for a copy of the relevant Scheme document.

 
Preservative Treated Wood Schemes (TW)

The original WPA Benchmark Approval Scheme for preservative treated timber was developed by a task group comprising WPA technical consultants, all the major suppliers of preservatives in the UK and independent research consultants. Its aim was to provide the timber supply chain with the means to respond to concerns about treated wood performance and to build buyer confidence in good quality, fit for purpose products.

This has now been developed into a series of three schemes which cover every stage in the treatment and production of preservative treated wood based materials.

WPA Benchmark Approved Formulations (TW)

The WPA Benchmark Approved Formulation (TW) scheme (formerly the WPA Wood Preservative Approval Scheme - WPAS) provides independent verification of the efficacy of an industrially applied wood preservative manufactured under ISO9001. Expert assessment is carried out on the laboratory and field test data used by manufacturers to give their customers guidance in the use of a preservative. 

 

The Scheme is specifically for preservatives applied by penetrating processes, typically vacuum-pressure. Approval is based on the minimum retention to be found in the 'analytical zone' after treatment to meet BS 8417 requirements for use class 4 and service life (15 or 30 years) combinations.

 

The data to be supplied in support of an application is clearly defined in a Scheme Document and is submitted to the WPA for assessment by an independent Efficacy Panel. 

The WPA Benchmark Approved Treater and Product (TW) schemes relate specifically to the durability of wood and wood based materials pre-treated by an industrial process. Individual treated wood products certificated under the Product scheme are verified as being compliant with BS 8417, the wood preservation code of practice - for either 15 or 30 years desired service life.

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 Industrial Wood Preservation Manual: Specification and Practice to provide guidance in achieving this performance benchmark.

 

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

WPA Benchmark Approved Treaters and Products (TW)

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The company being audited must be able to demonstrate that a consistent relationship exists, known as a Safe Relationship, between the penetration and retention requirements and the more easily measurable parameters of the treatment process, such as preservative concentration and pressure cycle, and then be able to control these parameters in subsequent treatment activities.

Modified Wood 

Schemes (MW)

A WPA Benchmark Approved Product (MW) scheme for modified wood used in ground contact is available. A quality scheme covering the manufacture of modified wood is currently under development.

 

Apply for Scheme Approval

If you are interested in submitting an application for a formulation, product or distribution service for any of the WPA Quality Schemes, Contact Us directly and ask for a copy of the relevant Scheme document.