We strive to offer the latest advances in timber window, door and shutter technology and materials. We are pleased to provide offer the Accoya® modified wood as part of our timber materials.

In this and the following 3 posts, we will outline the principles of the Accoya® wood modification process, properties of Accoya® wood and its increasing number of applications.

Modified wood is a term used to describe wood whose molecular composition has been altered, normally by chemical or thermal processes. This differs from a conventional preservative treatment where wood is impregnated with a biocide. An increasing range of modified wood products are available in the UK and it is essential, when specifying, that they are considered individually because their properties vary considerably.

Accoya® is the brand name of wood that has been modified by acetylation. This modification process replaces the water binding sites in the wood cell wall with acetyl groups that do not bind with water. These acetyl groups occur naturally in wood, albeit at much lower levels than in Accoya® wood.

Although Accoya® wood has only been on the EU market since April 2007, research on acetylated wood began as early as 1928. For this reason there is a wealth of knowledge on the performance of acetylated wood.

Acetylation significantly improves several wood properties. It increases durability of both sapwood and heartwood, and makes timber more dimensionally stable. For these reasons, Accoya® wood offers many advantages over unmodified wood. Some properties, such as ease of processing, strength, adhesion and ease of fixing, are relatively unaffected.

Radiata pine is the wood species presently used to manufacture Accoya®, although the process has proven effective on a range of other softwoods and hardwoods.The radiata pine is sourced sustainably and, since acetylated wood may be re-used, recycled and disposed of without the risks of environmental damage, Accoya® offers an alternative to using preservative treated wood (or increasingly scarce naturally durable timbers) for applications where there is a risk from decay.