WPA Wood selection Guide 2019-1.jpg

Wood modification is a term used to describe solid timber that has undergone a chemical, biological or physical process. This essentially creates a new timber product with enhanced performance properties – including durability and dimensional stability. These relatively new technologies are providing a wider choice of material for designers and architects to consider – popular for cladding, decking, windows, doors, landscaping and structural applications.​

Current commercially available modified wood technologies can be grouped into three main types


Here we focus on durability and features of modified wood that may be different from preservative treated or naturally durable timbers. For further guidance on strength  and dimensional stability please contact the relevant modified wood product manufacturer.

* NOTE: Some chemically modified wood products have sufficient field test data to demonstrate that they can achieve sufficient durability for use in ground and/or water contact. A minimum of 10 years field data is recommended. Please consult manufacturers for further information. 


The performance of modified wood products in fire can normally be enhanced using a secondary flame retardant treatment. Such treatments can also meet Building Regulations requirements, where applicable. The suitability depends on many factors including thickness and size of component. Please check for full details of recommended, independently assessed treatments and where they can be obtained.  Check with product manufacturer for details and remember that all the specification rules still apply.


Distributed in the UK by

Glenalmond Timber

Glenalmond timber.png
Accoya logo.jpg

Manufactured by Accsys


LIGNIA Wood Company Ltd

Medite Tricoya extreme.jpg

from Medite Smartply

WOOD: designed by nature, protected by innovation

The Wood Protection Association

5c Flemming Court, Castleford, West Yorkshire

WF10 5HW. United Kingdom

  • LinkedIn - White Circle
  • Twitter - White Circle

Privacy Policy | Corporate Code of Practice


© 2020 The Wood Protection Association

WPA 2020 Awards Logo.png