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WPA Resources:
Preservative Treated Wood

All WPA publications are free to view and download - simply click-on the relevant document image.

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The Buyer's Guide to Preservative Treated Wood

Preservative treatment provides wood with added durability. However, it’s a mistake to assume that all pressure treated wood is the same. Whilst one piece of treated wood may look very much like any other, the level of preservative protection could be very different 

WPA Industrial Wood Presertvation Code o

NEW WPA Code of Practice: Industrial Wood Preservation

A valuable and current reference of standards and good practice for treaters, specifiers and users of treated wood. This new publication supports the ongoing education campaign to raise awareness within the wood supply chain for the accurate specification of preservative treated wood products.

FAQs and Guidance Notes
Codes of Practice
Training and Webinars
Research Projects
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Learn about our campaign to promote

'fit for purpose' treated timber

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FAQs and Guidance Notes
WPA-TTF Guidance Note TW 1 (2) Wood Trea

Q. How do UK preservative treatment requirements (of BS 8417) relate to the Nordic NTR Scheme?

WPA TW 1: Guidance for Wood Treaters in the NTR Region

Timber treaters in the NTR region do not normally treat spruce for external, uncoated applications. However, this is permitted by BS 8417, the relevant UK standard. This fact sheet provides guidance to NTR treaters on how the treatment of spruce to meet a BS 8417 Use Class 3 specification aligns with current NTR classes and specifications. 

WPA-TTF Guidance Note TW 2 (2) Improving

Q. How can wood treaters assure effective quality timber treatments?

WPA TW 2: Guidance on Achieving Quality Treated Wood

 In 2017 TTF & WPA collaborated on a survey to identify the strategic priorities needed in order to grow demand for preservative treated timber. Analysis of the responses identified three priority areas for action. This note concentrates on the last point: To ensure independent verification of the treatment process. 

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Q. How does Brexit and the BPR affect the treatment or supply of treated timber?

WPA TW 3: Brexit and the EU Biocidal Products Regulation (BPR)

Treaters and users of treated wood (whether treated in the UK or imported treated) should, for the time being, see no impact on their practices and availability of treated wood from a regulatory viewpoint, now that the UK has left the EU. This Guidance will be updated if things change.

WPA Guidance Note TW 4 Indoor Air Qualit

Q. What impact does treated timber have on our indoor air quality?

WPA TW 4: Preservative Pre-treated wood and Indoor Air Quality

The indoor air environment is a complex subject that needs to consider the nature and source of any chemical, its ability to pass into the indoor air, its effect on humans when in the air, and the ability to remove it from the air by ventilation. 

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Q. How do you prevent mould growth on treated wood products?

WPA TW 5: Preventing Mould Growth on Treated Wood Products

Mould fungi can grow in the water layer on wet and damp timber surfaces. The growth is often fluffy and may be white, green, black or coloured, depending on the species and presence of spores. 

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Q. What are the current rules about creosote treated timber?

WPA TW 6: Use of Creosote and Creosote-treated Wood

There are specific permitted uses for creosote in the UK under the Biocidal Products Regulation - read all the details in this publication.

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Q. I'm a timber service treater, how do I get WPA Benchmark Approved Treater accreditation?

WPA TW 7: Benchmark Scheme for Preservative Treated Wood - Executive Summary 

The WPA offer two compliance routes to Benchmark accreditation. This note summarises assessment criteria and itemises costs - including discounts for Timber Trade Federation (TTF) members.  

WPA TW 8 Understanding Use Class 4 2020-

Q. How do I know if my ground contact treated timber will last and be fit for purpose?

WPA TW 8: Understanding Use Class 4 - Preservative Treated Wood  

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For wood in permanent ground or fresh water contact, or providing exterior structural support, Use Class 4 levels of protection MUST be achieved. Read why this is important and how it can be achieved through correct specification and treatment.

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Q. How do I know if my above ground treated timber will last and be fit for purpose?

WPA TW 9: Understanding Use Class 3 - Preservative Treated Wood  

For outdoor wood used above the ground, such as decking or cladding boards, Use Class 3 levels of protection apply. Read why this is important and how it can be achieved through correct specification and treatment.

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Q. Do internal construction timbers need to be preservative treated?

WPA TW 10: Understanding Use Class 2 - Preservative Treated Wood  

Where wood is used indoors, above ground and within the building envelope, but with an occasional risk of wetting, Use Class 2 levels of protection are required. Read why this is important and how it can be achieved through correct specification and treatment.

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Q. Do coated outdoor joinery timbers need to be preservative treated?

WPA TW 11: Understanding Use Class 3c (coated) - Preservative Treated Wood  

For outdoor joinery wood which is coated and used above the ground, such as window frames or cladding boards, Use Class 3c levels of protection are required. Read why this is important and how it can be achieved through correct specification and treatment.

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Q. What are the rules around permits for wood treatment operations in the UK?

WPA TW 12: Best Available Techniques (BAT) Conclusions for Timber Treatment Operations – UK Interpretational Guidance  

Timber treatment activities with plants having a capacity of more than 75m3 per day, (excluding anti-sapstain treatment), are required to operate in accordance with a regulated permit.  In December 2020 the EU published a new reference document on how to determine permit conditions and best environmental practice: EU Best Available Techniques (BREF) conclusions for Timber Treatment Operations.

 

On 6th January 2021, the UK IPC Regulators Group issued interpretational guidance on the recent EU BAT conclusions document - the UK IG Note 2021. This will be used by the relevant UK regulators when determining new permit applications and reviewing existing permits.

Guidance Note TW 12 covers the background and implications of both documents and looks at the new permit process.

WPA TW 13 Installing Treated Fence Posts

Q. What do I need to know when installing treated timber fence posts?

WPA TW 13: Installing Preservative Treated Fence Posts - Best Practice Guidance  

All pre-treated wood products are impregnated in their finished form and are designed to be installed without modification.

This Guidance Note details, with simple illustrations, everything you should consider when preparing and installing both ROUND and SQUARE sawn softwood posts, pre-treated with a preservative for fencing applications.

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Q. What do I do with unwanted treated wood / How do I dispose of treated wood waste safely?

Guidance Note 02/09: Dealing with Treated Wood Related Waste Streams

For those involved in the business of industrial wood preservation, this publication is intended to provide information about current waste minimisation options and regulatory responsibilities as a basis for decision-making.

 Trackwork  who are WPA Members, run a dedicated treated wood disposal service. Energy from their waste plant is audited, monitored and licensed by the Environment Agency and burns hazardous waste wood to generate electricity. This goes on to power their Doncaster site and exports surplus energy to the National Grid.

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Quality Guidance Note 2 (QGN2): For use with BS EN ISO 9001:2015

Relating to the controlled preservation of wood and wood-based materials to improve their durability.

TO PURCHASE ONLY - CONTACT US

This document can be used as part of a Quality Management System audited by a Certification Body and as part of a quality plan audited under the WPA Benchmark scheme. QGN2 forms the basis of the National Highways Sector Scheme 4 for the preservative treatment of fencing and is referred to directly in Highways England quality scheme documents. QGN2 is an operating document of the WPA. It is a ‘controlled document’ in Sector Scheme 4 and is an essential part of the verification audits required by the scheme and carried out by UKAS accredited Certification Bodies.

 
 
WPA Codes of Practice
WPA Industrial Wood Presertvation Code o

NEW WPA Code of Practice: Industrial Wood Preservation

A valuable and current reference of standards and good practice for treaters, specifiers and users of treated wood. This new publication supports the ongoing education campaign to raise awareness within the wood supply chain for the accurate specification of preservative treated wood products.

This document replaces the former WPA Manual: Industrial Wood Preservation - Specification and Practice.

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WPA Code of Practice: Timber Treatment Plants

Safe Design, Installation and Operation

This publication was produced in collaboration with UK Regulatory bodies and is designed to guide those responsible for the design, installation or operation of timber treatment plants.

 
Preservative Treatments for Wood: Training and Webinars

NEW Making the most of wood WEBINAR 2021

Hosted by WPA CEO Gordon Ewbank this educational training webinar details the principles involved with the correct specification and use of preservative treated wood.

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Free On-Line Courses from Wood Campus

Dip into these free CPD courses, many RIBA accredited, for information about a specific topic, or complete the full course. You don’t need to pre-register for access. On successful completion of a course and assessment, you will be asked for your email so Wood Campus can send you a CPD certificate.

 
Preservative Treatments for Wood: Research Projects
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WPA Field Trial of Preservative Treated British Softwoods - Year 5 Observations

To assess the durability in differing test site conditions

WPA in collaboration BRE commissioned a long term controlled field trial of sawn and pressure treated British Softwood posts at two sites with differing soil conditions - here's a summary of the results so far. 

WPA Guidance Note TW 4 Indoor Air Qualit

Preservative Treated Wood and Indoor Air Quality

The WPA commissioned Building Research Establishment (BRE) to help them understand how treated timber performs in the context of air quality within buildings to actively support the continued safe and appropriate use of wood preservatives to enhance the performance of timber used in construction.

Need to get in touch?

If you cannot find the answer to your question within any of the listed publications, please get in touch.

 

We have knowledgable people based in the UK office as well as numerous technical consultant members we can call upon to assist you.

Go to CONTACT US page or give us a call.

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