On this page, please find a number of Frequently Asked Questions relating to Accoya wood and Accoya products. If you still have questions please do contact us.

I’ve been told that treated softwood is the same as Accoya. Is this correct?

No. Accoya is softwood that has been modified by a non-toxic process called acetylation. Treated softwood is softwood that has been partially impregnated with a biocide. Advantages of Accoya over treated softwood include: more reliable and longer lasting rot resistance, less coating maintenance, better thermal insulation and less risk of doors and windows jamming or warping with changes in humidity.

How can Accoya be considered sustainable if it uses wood from New Zealand?

A common measure of sustainability is the carbon footprint of a material and it is true that transport is a contributing factor to a larger carbon footprint. However, transport is only part of the equation and studies that also take account of the rapid carbon sequestration during the growth of the trees used for Accoya and the carbon value of by-products (which are used by other industries and are therefore offset against carbon costs in our process) show that the carbon footprint of Accoya is within the range of other timbers and significantly less than that of other man made materials such as uPVC, aluminium, concrete and steel.

How does the Accoya warranty work?

We warrant both the rot resistance and the stability of Accoya for 50 years above ground and 25 years below ground. We do not warrant the performance of any other products used in conjunction with Accoya. Warranties for such products need to come from their manufacturer or from the company that has assembled the products with Accoya. For example, the full warranty on an Accoya window needs to come from the window manufacturer, though it is supported by a warranty that specifically relates to the Accoya elements of the window.

In the event of any claim relating to the Accoya elements of a product, the applicant would need to provide evidence of purchase. Please refer to the Accoya warranty for full terms.

Is Accoya suitable for the manufacture of products other than external windows and doors?

Yes. Since Accoya has consistent performance throughout it can be easily machined using conventional woodwork tools and machinery for the construction of any timber product. Other typical applications include claddingdeckinggarden furniturelandscaping and civil works.

How will the thermal performance of an Accoya window compare to that of one made from softwood or hardwood?

Accoya is a 40% better thermal insulator than typical joinery hardwood and 4% better than softwood. The impact of this on the thermal performance of any particular window will depend on the design of the window and the quality of the glazing but all other things being equal an Accoya window will almost always be more thermally efficient than either a hardwood or a softwood window.

Is Accoya easy to repaint when I need to?

Yes. The paints used on Accoya products are the same as used on other types of wood. In fact, the exceptional durability and stability of Accoya mean that not only does it require less frequent repainting than other timbers, the repainting process is often simpler and quicker since the substrate is stable and not subject to the shrink and swell that affects other woods.

How can you say that Accoya will last more than 60 years if it hasn’t been commercially available that long?

The generic term for Accoya is acetylated wood and acetylated wood had been studied by wood scientists for many decades before Accoya came to the market. Consequently, there are examples of long term trials where acetylated wood has demonstrated its exceptional performance.

In addition, there is a standard European test for the durability (rot resistance) of timber by which it is possible to directly compare the durability of Accoya with that of any other timber and since we know what to expect from the other timbers we can conclude what to expect from Accoya. Both the BRE (Building Research Establishment) and TRADA (the UK’s leading independent timber research station) support the claims made about the durability of Accoya.

Is Accoya a hardwood or a softwood?

The brand Accoya relates to a modification process called acetylation that can be applied to a limited number of timber species, some hardwoods and some softwoods. It is therefore classed as a modified wood, not a hardwood or a softwood.
The version of Accoya most commonly used for joinery manufacture starts life as a softwood called Radiata pine. However whilst the acetylation process doesn’t change the appearance of the wood it significantly improves the rot resistance (durability) and stability of the wood, making it significantly more durable than joinery hardwoods such as oak, iroko and even teak.