The Buyer’s Guide to Preservative Treated Wood

Date Published

8 November 2022

Document Type





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

Key Information

The WPA Code of Practice for Industrial Wood Preservation (January 2021) groups the applications for treated wood into Use Classes, the main three being:

Interior: Use class 2

Exterior: Use class 3(u) and Use class 4

Case studies

The Macallan, the distinguished single malt whisky, has been produced in Speyside since 1824, and its new building is set into the sloping contours of the estate grounds.

The latest addition to the University of Kent campus is the Colyer-Fergusson Building, containing a first class concert hall in which timber is used to provide the ideal warmth and acoustic qualities for music performance.