Raising the bar on timber protection

Wood Protection Association (WPA) Director, Neil Ryan, explores the support available to help ensure treated wood is specified and installed correctly.

It’s just over two years since the Code for Construction Product Information (CCPI) was published, in response to one of the key findings of the enquiry into the Grenfell Tower fire, which confirmed that shortcomings in product information had contributed to the disaster. 

Concern was raised about inadequate specifier guidance, product information, marketing materials and performance testing claims. Undoubtably, there are still many instances where the code – still a voluntary requirement – is not being followed.

The Code calls for information on construction products and systems to be clear, unambiguous, accurate, up to date and accessible. This is so that any competent individual working with or installing the products can understand how and where to use them, how they will perform in service and the limitations of their use.

Fit-for-purpose timber products

Installing a treated timber product which is fit for purpose is important and at times, critical, be that timber which is treated with a flame retardant, preservative or wood modification process.

Product information which is vague, ambiguous and uses potentially misleading terms can lead to the wrong product being used for the wrong application, leading to in-service failures.

The benefits of being able to demonstrate best practice in this area is clear. Ensuring your company is ready to offer customers the best products and the highest levels of customer service, by adhering to industry standards and providing the technical information to support that behaviour, enhances your reputation and your potential to improve sales.

Timber knowledge

The WPA prides itself on being recognised as an authoritative trade body, with the experience and knowledge to advise on all matters concerning the industrial treatment of timber – through preservation, wood modification or factory applied flame retardants. 

Through its work and affiliation partnership with Timber Development UK (TDUK), the WPA provides guidance to specifiers, contractors, engineers and architects on the best ways to ensure wood is fit for its intended purpose.

Free and accessible information

Over the past five years we have been building a comprehensive library of timber treatment resources – and it never stops growing – from Guidance Notes, Codes of Practice and Information Sheets to webinars and Point of Sale material. These resources are valuable assets for WPA and TDUK members and can be used for internal training.  But they can be shared for wider education too, using the information for both commercial and marketing purposes.

In every aspect of WPA’s guidance, we always refer to any appropriate corresponding British Standard and do our best to simplify the information – making it more accessible and relevant for our sector. 


Timber and fire performance
The factory application of a flame retardant (FR) treatment uprates timber’s ‘reaction to fire’ classification. Untreated wood-based materials typically have Euroclass ratings of D or E, but FR treatment can improve that to Euroclass B or C as required by the specification and end use.  

Guidance Note WPA FR6 summarises the requirements of an effective and accurate specification and points to other WPA documents for further reference.

Treated timber action plan
We have created a plethora of information to raise awareness of the importance of buying and installing correctly treated timber for ground contact applications. Working with TDUK as part of its Treated Timber Action Plan, we are seeing positive results with more timber treaters gaining WPA Benchmark Approved Treater status.

Timber durability 

Depending on its natural durability and end use, a timber component may need extra protection against decay and insect attack, through preservative treatment or wood modification. 

The Use Class system (ref BS 8417) categorises end use applications and assigns levels of protection required. Where wood is permanently exposed to the weather and wet for extended periods or used as external structural support such as deck joists, this is Use Class 4 (UC4). UC2 is for internal construction applications such as roof trusses and floor joists and UC3 for exterior, out of ground applications such as fence rails, decking boards and timber cladding. 

WPA Guidance Notes TW8, TW9, TW10 and TW11 explain these requirements further. If you are manufacturing or supplying industrially treated timber, download our resources to help you and your customers. And if you have any timber treatment questions, get in touch, we’re here to support and promote best practice.