Accoya Wood Performs Well in 5-Year Tests

http://www.woodworkingnetwork.com/wood/lumber-data-trends/Accoya-Wood-Performs-Well-in-Five-Year-Field-Tests-135432623.html?utm_source=dlvr.it&utm_medium=facebook

The link is to an article in Woodworking Network that describes the very positive results testers obtained in comparing a technologically-modified wood to either untreated or chemically treated lumber species. In all cases, this new wood surpassed the others in durability and resistance to decay and rot.

Accoya is a technologically modifed wood, engineered and produced by Accsys Technologies.
There are traditionally two major concerns with wood as a building material:
-dimensional stability
-durability
Wood is characterized by an abundance of chemical groups called free hydroxyls. These absorb and release water according to the environmental conditions they are exposed to, and this causes dimensional variations. Further, the free hydroxyls are where breakdown by enzymes begins the process of decay and rot, not to mention attack by organisms seeking food.
A process called acetylation changes these free hydroxyl groups into acetyl groups, which are far more impervious to variation in water content, hence are much more dimensionally stable. This acetylation process uses a naturally-occurring compound called acetic anhydride, which comes from acetic acid (vinegar in its liquid form). In addition, these acetyl groups are not digestible, hence are invisible" to enzymes and other organisms, so resistance to decay is multiplied.
As a result, acetylzed woods offer the following performance characteristics:
-Dimensional stability:
 -Swelling and shrinkage are reduced by 75% or more;
 -Manufactured elements (such as doors and windows) function better and experience longer life;
 -Finishes have longer lives (less prone to cracking or crazing)
-Improved coating abilities: -Easier to coat: less preparation and sanding required;
 -Less grain-raising;
 -Greater UV resistance.
-Machineability: -A more homogenous material machines well;
 -Improved tolerances for parts and components.
-Sustainability: -Uses sustainably-sourced woods, and regionally produced certified species;
 -The acetylation process is environmentally friendly, does not rely on toxic chemical compounds to improve the durability of the timbers;
 -Acetylated woods can obtain guarantees of up to 50 years in an outdoor usage, 25 years for in-ground uses; this exceeds the performance of traditional chemically-treated lumbers.
 -Scraps and sawdust can be recycled or put to further uses, which is not always the case for chemically-treated woods;
 -Because locally-grown timbers can achieve and exceed the durability of exotics, costs of remote-area logging, transportation to ports and intercontinental shipping can be curtailed.
Summary:
In summary, for architects, builders, manufacturers and end-users, consideration of acetylzed woods can alleviate concerns of environmental and/or performance compromises when compared to other building materials.
For further reading about acetylzed woods, the acetylation process, and Accoya, see www.acoya.com