Timber Development UK Classification

The Wood Protection Association (WPA) in collaboration with Timber Development UK has produced a Buyers Guide to Preservative Treated Wood so that you, our customer, understand the class of treated timber needed before ordering.

As a member of the Timber Development UK, we want to ensure our buyers get the best from our timber so understanding the classifications is vital. 

The preservative treatment provides the 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.

That’s because national technical standards for wood preservation require that the loading and penetration of preservatives, impregnated into the wood, is tailored to the desired end-use.

What class should you use?

Illustration of TTF Classes

Please look out for the classifications on our product sales information and order forms and if you have any questions, please ask your sales contact or contact the below.

The Wood Protection Association
Tel: 01977 558 274
Email: contact@thewpa.org.uk


Timber Development UK
Tel: 020 3205 0067
Email: info@timberdevelopment.uk