Quality Assurance

ISO 9001 Management Systems

ISO9001 is the international standard that certificates the management systems operated by a business in manufacturing a product. Certification under ISO9001 is a mandatory requirement for chemical and coating suppliers seeking membership of the WPA.

WPA Approval Scheme for wood preservatives and flame retardants

For industrially applied wood preservatives and flame retardants manufactured under ISO9001, the WPA operates a product approval scheme. The aim of the scheme is to provide independent assessment and verification of the performance and efficacy data on which the manufacturers treatment recommendations are made.

Participation in the Approval Scheme by wood preservative manufacturers is voluntary. For suppliers of flame retardant treatments where their performance is a safety critical factor in building design WPA approval is a mandatory requirement for use in a WPA quality assured process.

For the current schedule of WPA approved wood preservatives click: WPA approved

For details of WPA approved flame retardant formulations, treaters and materials click here

Quality Assurance 

WPA operates a number of product approval and quality assurance schemes which benchmark and verify the quality of a wood preservative or flame retardant formulation, the treatment process and treated wood materials against specific UK and European performance standards. These quality schemes are:

- WPA Benchmark Quality Scheme for preservative pre-treated wood

- WPA Benchmark FR Quality Scheme for flame retardant application processes and materials

- WPA FR Build Quality Scheme for timber frame components approved by Structural Timber Association 

WPA Benchmark 
This scheme relates specifically to the durability (resistance to biological degradation) of wood and wood based materials pre-treated with preservative by an industrial process. 

Individual treated wood products certificated under this scheme are verified as being compliant with BS8417, the wood preservation code of practice - for either 15 or 30 years desired service life.


WPA Benchmark Certificated preservative treated wood products and service treaters


Benchmark Certificated Product/Service


Bond Timber
PL12 5BW


Certificate No: TW 2012001
Redwood components preservative treated with Tanalith E in accordance with BS 8417 for Use Class 4, ground contact applications.

Tel: 01503 240308
E: andy@whbond.co.uk
W: www.whbond.co.uk

Calders & Grandidge
194 London Road Boston
PE21 7HJ


Certificate No: TW2011004
Round and sawn redwood components for ground contact (Use Class 4) applications and, redwood and whitewood components for out of ground (Use Class 3) applications treated with Osmose AC500 preservative

Tel: 01205 312420
W: www.caldersandgrandidge.com


Scanpole BBH
Alexandra Dock
Newport South Wales
NP20 2WA   

 Certificate No: TW2011003
Creosote treated pine poles, sleepers, fencing and Osmose AC500 treated pine poles and fencing – Use Class 4   


Tel: 01633 235845
E: info@bbhpreservingwood.co.uk
W: www.bbhpreservingwood.co.uk

Södra Timber Ltd
Peel Ports
Sheerness Docks
ME12 1RS

Certificate No: TW2012005
Softwood preservative treated with Osmose Celcure AC350 and Protim E406 in accordance with BS8417 for construction applications

Tel: 01285 646000
E: ukinfo@sodra.com
W: www.sodra.com/en/wood/products-for-uk-and-ireland-timber.co.uk

Cordiners Sawmills Ltd North Deeside Road
AB31 5PY

Certificate No: TW2016001
Sawn and round pine treated by a high pressure impregnation process in accordance with BS8417 - 15 years desired service life


Tel: 01330 823366
E: info@cordiners-sawmills.com
W: www.cordiners-sawmills.com



Glenalmond Timber
Shore Road
Perth Harbour

Certificate No: TW2012002
Timber components preservative pre-treated by low pressure impregnation with Vacsol Aqua in accordance with BS 8417 for constructional applications

Tel: 01738 587988
E: enquiries@glenalmondtimber.com
W: www.glenalmondtimber.com



Palmako AS
Näituse 25
50409 Tartu


Certificate No: TW201302
Incised spruce posts pressure treated with Tanalith E8000 in accordance with BS8417 for Use Class 4 ground contact applications.

Tel: +372 507 6924
W: www.imprest.ee



The Woodyard
CM16 6TT

Certificate No. TW2017001
All solid wood materials supplied under the Q_Deck, Q-Slip, Q-Garden and Q-Shades Brands


Tel: 01992 578877



James Davies (Abercych) Newbridge Sawmills
Cenarth Newcastle Emlyn Ceredigion
SA38 9LA


Certificate No: TW2012003
Pine and Douglas fir (round and sawn) treated with Tanalith E for a Use Cass 4 application, 15 year desired service life

Tel: 01239 682477
E: info@jamesdaviessawmills.co.uk
W: www.jamesdaviessawmills.co.uk


M & M Timber
Hunt House Sawmills
Clows Top
Kidderminster DY14 9HY

Certificate No: TW2011002
Osmose MicroPro treated radiata pine, home-grown pine, larch and Douglas fir Incised Agricised round posts

Tel: 01299 832611
E: sales@mmtimber.co.uk
W: www.mmtimber.co.uk

Rafferty Roof Trusses
Unit 2 169a Agivey Rd Aghadowey Coleraine
BT51 4AB

Certificate No: FRB201401
Preservative impregnation of general carcassing and construction timbers (joists/studs/rimbeam/plywood) in accordance with BS8417 desired service life specifications

Tel: UK 0845 5217626
Ireland: 02870441061
E: info@raffertyroftrusses.co.uk
W: www.raffertyrooftrusses.co.uk


Walford Timber
The Sawmills Walford Ross-on-Wye

Certificate No: TW2011001
The “PermaTimber” range


Tel: 01989 563614
E: info@walfordtimber.co.uk
W: www.walfordtimber.co.uk

WPA Benchmark FR 
This quality scheme relates to both the factory process used to apply a WPA approved flame retardant formulation as well as the materials that are produced i.e. solid wood and wood-based materials such as panel products. Application processes are audited annually to ensure they remain compliant with WPA Benchmark FR scheme criteria.

Materials certificated under this scheme must use a flame retardant manufactured under an ISO9001 quality management system and which have their fire test classifications and performance data approved under the WPA's independent product approval scheme. 

The WPA approval scheme for flame retardants and Benchmark FR process and materials approval scheme interlock with one another to provide specifiers with reassurance about the quality and performance of flame retardant treated wood.

WPA Benchmark FR approved flame retardant formulations, treaters and materials

WPA Benchmark FR Processor


Contact details

Lonza Wood Protection
Wheldon Road Castleford
West Yorkshire WF10 2JT


Tel: 01977 714000 
W: www.lonzawoodprotection.com/




WPA Benchmark FR Materials Manufacturer/Supplier


Meyer Timber / Panelco
Hadleigh Park
Stoke on Trent
ST11 9LW


Tel: 0844 391 4245
E: sales.stoke@meyertimber.com
W: www.meyertimber.com


Co. Waterford





Tel: +353 (0)5185133
E: info@mdfsob.com
W: www.mdfsob.com



Timbmet Ltd
White Horse Business Park
Standford in the Vale


Tel: 01865 860350
E: oxfsales@timbmet.com

WPA FR Build
This quality scheme is operated by WPA for the Structural Timber Association (STA). It relates to wood, panel products and engineered wood components defined in STA Product Paper 1 that have been treated with an STA approved FR Build flame retardant to provide protection from fire in the construction phase of a building. The WPA FR Build quality scheme provides third-party certification of the factory process used to apply the STA approved flame retardant.

WPA FR Build certificated products for timber frame buildings
Benchmark FR Build Certificated Product/Service
Contact details

Södra Wood Ltd
Peel Ports
Sheerness Docks Sheerness
ME12 1RS

WPA Certificate No: FRB2012001

For the fire retardant treatment of wood, wood based sheet materials and engineered wood products in accordance with the Structural Timber Association.

Tel: 01795 596476
E: ukinfo@sodra.com
W: https://www.sodra.com/en

Glenalmond Timber
Shore Road
Perth Harbour
Perth PH2 8BD

WPA Certificate No: FRB2011001

Flame retardant treated general carcassing and structural elements (joists/studs/rimbeam/plywood) in accordance with the Structural Timber Association FR Build requirements.

Tel: 01738 587988
E: enquiries@glenalmondtimber.com
W: www.glenalmondtimber.com

James Donaldson & Son
Elm Park Sawmills
Fife KY8 4PS


WPA Certificate No. FRB2017001

Flame retardant treated general carcassing and structural elements (joists/studs/rimbeam/plywood) in accordance with the Structural Timber Association FR Build requirements.

Tel: 01333 422222
E: elmpark@donaldson-timber.co.uk
W: http://www.don-timber.co.uk/

County Waterford Ireland

WPA Certificate No: FRB2013001

SmartPly 18 mm FR Build OSB/3  
SmartPly 15 mm FR Build OSB/3

Tel: +353 (0)5185133
E: info@mdfosb.com
W: www.mdfosb.com

Rafferty Roof Trusses Ltd
Unit 2 169a Agivey Rd Aghadowey Coleraine
BT51 4AB

WPA Certificate No: FRB201302

Flame retardant treated general carcassing and structural elements (joists/studs/rimbeam/plywood) in accordance with the Structural Timber Association FR Build requirements

Tel: UK 0845 5217626
Ireland: 02870441061
E: Basil@raffertyrooftrusses.co.uk
W: www.raffertyrooftrusses.co.uk

Trade Fabrication Systems Ltd
18 Chesford Grange, Woolston,
Warrington WA1 4RQ

WPA Certificate No: FRB/2015001

Product certificated: Norbord No Burn 18mm OSB/3

Tel: 01925 821199

National Highways Sector Scheme 4

National Highways Sector Schemes exist to ensure that quality management practices are applied consistently to materials supplied for motorway and county trunk road contracts. Every aspect of highways construction and repair is covered by a specific sector scheme. Procedures for treated wood fencing specification and procurement is covered in Sector Scheme 4 (SS4). Companies must be ISO9001 certificated as SS4 compliant before they can bid for treated wood supply contracts on highways projects.

Much of the SS4 Scheme Document published by UK Accreditation Services (UKAS) is based on and makes direct reference to WPA Quality Guidance Note 2 (QGN2) and the specifications and practices set out in the WPA Manual of Wood Preservation.

WPA Treaters that are ISO9001 - SS4 Certified

SS4 Certificated supplier


A & J Scott
T: 01668 217288


Bond Timbe
Saltash, Cornwall
T: 01503 240308


BSW Timber Group
T: 0800 587 8887

H S Jackson &  Son Fencing 
T: 01233 750393



Balcas Timber

Hales Sawmills










WPA Quality Assurance and Product Approval Schemes

Setting the standard for wood preservation and flame retardant treatment quality

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