Recently added FAQs:

• Is there any faster-growing timber that would be suitable for acetylation? While faster growing timber species do exist, like bamboo, the pine we use has been selected because it’s both fast-growing and high-yield. These advantages help Accoya meet rising demand for low impact timber products by sourcing from well-managed forestry in New Zealand. To learn more, see the sustainability section of accoya.com.
• What is the co-product of acetylation and what happens to this co-product? Acetic acid is the co-product of the acetylation process, which we either sell for use in various other industries or can convert back into acetic anhydride, contributing to a closed loop process.
• Can you burn Accoya and is this sustainable? Where possible, recycling is favourable over burning Accoya wood as the end product is 100% recyclable. This is unlike materials such as wood plastic composite (WPC), which are challenging to recycle due to the mixture of wood and plastic.
• How to check if timber is sustainable? For timber to be truly sustainable it needs to be certified by a credible third party. This makes it harder for organisations to make false claims and greenwash their products.
• Does Accoya use sustainable timber, and how can timber be sourced sustainably? Accoya wood is made from FSC® certified pine. The species we use is high-yielding and grows at a rapid pace, making it an ideal sustainable timber for our process because it’s an easy-to-renew material. Illegal logging causes strain across many wood species, with tropical hardwoods particularly feeling this negative impact due to its slow growth. However, because we source from New Zealand - a country with strict policies around deforestation - we’re confident in the sustainability credentials of the timber.
• What will uncoated Accoya look like over time? Like other wood species, uncoated Accoya wood will weather over time to an elegant slivery grey colour when left outside and exposed to the elements.

• How to clean and maintain an Accoya wood deck? Wood decks are subject to natural weathering and require regular cleaning.  Each deck requires an individual maintenance interval, depending on location, use intensity and personal preferences.
• What are the benefits to a home owner? What is it that makes Accoya so special and stand out from other wood products?
• What is Accoya wood made from? Accoya wood is made from radiata pine trees. These are sourced and taken to our production facilities in the Netherlands where they undergo a modification process, more specifically known as Acetylation. This process turns the radiata pine wood into the worlds most stable wood, Accoya.
• Is Accoya Hardwood or Softwood? Accoya is a modified wood. Accoya begins life as a softwood known as radiata pine but it is modified through the Acetylation process. This makes it much stronger, yet it remains real wood and is non-toxic. It is class 1 durability, extremely stable and structurally certified.
• Where is Accoya wood grown? Accoya wood begins life in sustainably managed forests in New Zealand as a tree species called Radiata Pine. These forests are all FSC approved. The Radiata Pine is fast-growing and is shipped from here to the Netherlands for the modification process.
• What is Cradle to Cradle Certified®? Cradle to Cradle Certified® is the global standard leading brands use to verify that their products are safe, resource efficient and responsibly made.
• Why do we use acetic anhydride? Acetyls are naturally present in wood, helping to protect it from the effects of water which can make it warp and rot. We use acetic anhydride to enhance this effect, boosting it by changing water-loving hydroxyl groups into water-repelling acetyl groups.
• Why is the wood sourced from New Zealand? Our main feed stock for Accoya production is fast-growing and high-yield pine from New Zealand. Its quick growth cycle helps us meet the rising demand for building materials without compromising on sustainability.
• What lengths can I buy Accoya in? Accoya wood is available in a large selection of dimensions and lengths. This helps reduce wastage and selection time during production, unlike traditional hardwoods which are typically purchased in random widths and lengths.
• What paint to use on Accoya? Multiple finishing options are available for Accoya, from natural-looking oils to high performance paint systems, all in an infinite variety of colours. There is not one specific brand of paint to use. Although, within each brand there may be some products that are better suited for use on Accoya than others in certain situations. It is also important to follow the correct procedures for preparation and application of the paints and stains. Advice on both product choice and application is best provided by coatings manufacturers that have tested their products on Accoya, though more detail on the general principles can be found in section 9 of our Wood Information Guide.
• Is Accoya expensive? Accoya wood is sold to manufacturers who create high performance low maintenance Accoya windows, doors, cladding, decking and more.
• What is PEFC®? PEFC® stands for Programme for the Endorsement of Forest Certification.
• How does Accsys ensure the quality of Accoya wood? One of our company values is that “we are committed to quality, safety and sustainability” – and we build that into everything we do, from our FSC chain of custody certification to our KOMO, Cradle to Cradle Gold and other accreditations.
• How is Accoya wood sold? Our sales network is actually far bigger than our direct sales team. We work with distributors all over the world to support Accoya’s entire route into the market: from manufacturers, woodworkers and joiners all the way through to the end users.
• What makes Accoya so special? Wood is an amazing material with many possibilities and practical applications. One of the major drawbacks of wood though, especially softwood, is how it interacts with water. Moisture causes the wood to swell and shrink, and accelerates damage and decay.
• What is FSC®? FSC® stands for the Forest Stewardship Council®, a timber certification system co-founded by the World Wildlife Fund (WWF). Trees in FSC® certified forests are grown and harvested according to a strict set of guidelines that benefit the environment. These guidelines include, but are not limited to:
• I would like to promote my Accoya products. Do I need permission? As an Accoya wood customer, please request the brand guidelines from either your distributor or directly to Accsys. The guidelines have been put in place, and should be rigorously adhered to, in order to protect the Accoya brand, and deliver clear communication with consumers.
• I am a manufacturer do I need to be trained? Accsys offers an Accoya training program and we would encourage all manufacturers planning to use Accoya to contact their distributor or Accsys directly to arrange. The Approved Manufacturer status also brings a number of benefits which support market activity.
• Will Accoya turn grey? Because Accoya wood has a very high resistance against wood destroying fungi, a popular choice is to use it in various applications uncoated. It will weather naturally to a silvery-grey colour, due to physical and biological processes that take place within the top layer
• Do I need to coat Accoya wood? From a technical performance perspective, in respect of attributes such as durability and dimensional stability, there is no need to finish Accoya wood for cladding and decking applications. However, joinery applications are more complex so it is recommended that you seek expert advice before using Accoya for uncoated windows and doors.
• What fasteners should I use with Accoya wood? Accoya wood can be fixed in the same way as other commonly used softwood species and the same general rules regarding pre-drilling, countersinking and keeping sufficient distance from the edges should be applied. Like most durable woods, Accoya contains a small amount of acid. It is therefore strongly recommended that corrosion resistant fixings, such as high quality stainless steel, are used.
• Can you sand Accoya wood? Sanding Accoya wood presents no challenges. Tests have shown that it is often not necessary to sand Accoya wood between coats of water based coatings since fibres scarcely ‘bloom’ or rough the surface after moisture absorbance. Nevertheless, advice should be taken from your coatings partner on good process detail, as poor practice may result in reduced surface aesthetics. Avoid aggressive types of sanding and orbital palm sanders if a smooth flat surface is required.
• Can you drill Accoya wood? Accoya wood drills in a manner and quality consistent with most softwoods. For deep drilling, care may be needed to remove debris, given the fine smaller shavings that are produced by Accoya wood. For dowel connections it is important that the diameter of the drill is no smaller than the diameter of the plug to prevent splitting.
• How should I store Accoya wood? Accoya wood that needs further processing, gluing or coating should be carefully stored (preferably horizontally), in closed and well ventilated sheds to prevent water/moisture uptake.
• How can I tell it is Accoya wood? Accoya wood is primarily identified by its packaging labels, which feature the Accoya logos. Additionally the batch number and grade (A1 and A2) associated with each board is typically printed on its surface.
• Is Accoya slip resistant? The slip resistance of all wooden (decking) boards and many other materials depends on factors such as degree of weathering, surface profiling, coating, wetness of the boards and maintenance – i.e. the presence of a biofilm of bacteria, fungi and algae. Test methods vary greatly across the world (even throughout Europe) and only a few countries have official requirements covering the slip resistance of flooring surfaces.
• Is Accoya structural graded? The Accoya acetylation process improves hardness and compression strength significantly. Accoya is approved for a general building approval by the German Institute for Building Technology (DIBt) for load bearing structural applications. This DIBt approval qualifies the strength class of A1 and A2 solid Accoya timber based on the European strength class system of C classes (EN338).
• 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. While it’s true that transport emissions can be an important contributing factor to a larger carbon footprint, they are only part of the equation. Studies that also take account the rapid carbon sequestration during the growth of the pine trees used for Accoya, and the carbon value of by-products (which are used by other industries and are therefore offset against carbon impacts in our process) show that the carbon footprint of Accoya wood is significantly less than those of other man-made materials such as uPVC, aluminum, concrete and steel.
• What benefits does Accoya have over Wood Plastic Composite products (WPC)? Wood Plastic Composites (WPC) are made from a mix of plastic fibres and wood products. Due to their plastic contents, WPC decking boards tend to be more slippery than Accoya decking boards. Accoya decking boards have been thoroughly tested against a range of competitor products, including WPC, and they are found to have higher slip resistance when used across a range of applications including shower areas, swimming pools, shop entrances, exterior staircases and even public kitchens.
• I’ve been told that treated softwood is the same as Accoya is this correct? No treating softwood certainly improves the performance of the wood but it comes nowhere near to delivering the same performance benefits of Accoya.
• Does the process affect the colour of the wood? There is a slight bleaching of red colours and a slight darkening of the outer surface of other wood. This is, however, insignificant compared to other processes such as thermal modification which deepens the colour of wood to dark brown.
• Does the strength of the wood change during the process? Acetylation causes no significant change in the strength of wood.
• Does Accoya have different paintability? Yes. Due to the improved dimensional stability of Accoya wood and the significant reduction in swelling and shrinking, maintenance of coatings can be increased to up to 2 times the normal life of coatings applied to non-modified woods.
• Can acetylated wood be glue laminated or finger-jointed? Yes, acetylated wood can be glue laminated and finger-jointed. Wood cannot, however, be acetylated after it has been laminated or finger-jointed as the process would damage glue lines and result in de-lamination.
• Does Accoya have different gluability? In general, Accoya wood can be glued using most commonly used wood adhesive systems. Particularly good results are obtained with polyurethane (PU), emulsion poly isocyanate (EPI), epoxy and phenol resorcinol formaldehyde (PRF) adhesives. The results of gluing with polyvinyl acetate (PVAc) improve with longer clamp times but it should not be solely relied on for strong joints. Melamine urea formaldehyde (MUF) should be avoided. When gluing Accoya wood it is strongly recommended to test first and if needed contact your adhesive supplier(s) as they have in-depth knowledge of the gluing process and their adhesives. Use should always be in line with best practice, design and performance specific demands. Gluing Accoya and products offered by adhesive system partners is part of the Accoya Approved Manufacturer training programme.
• How is Accoya disposed of at the end of its life? Accoya’s approach to end-of-life and customer reclamation endeavours to maximise material use. We reclaim off-cuts from manufacturers and use them in the production of Accoya’s sister-brand, Tricoya®. This ensures that waste wood gains a new lease of life while carbon remains locked in.
• Does wood need to be kiln dried before acetylation? Yes. Because the acetic anhydride used reacts with water as well as with hydroxyl groups in the wood, the lower the moisture content of the wood, the more efficient and cost effective the process.
• Why has no-one commercialised this process before? There was little demand for the commercialisation of acetylated wood when there were ample supplies of tropical hardwoods and less stringent legislation governing the use of toxins in wood treatments.
• Can Accoya be used in marine applications? Yes. Accoya wood is ideal for boat decks, trimmings and freshwater applications such as canal linings.
• What applications can Accoya be used for? Accoya offers a superior level of performance to traditional softwoods, often exceeding that of even the most durable tropical hardwoods.
• How environmentally friendly is Accoya wood? Accoya wood is non-toxic and 100% biodegradable. By enhancing the durability and stability of the fast-growing pine we use, Accoya wood provides advantages over scarce slow-growing (and often unsustainably sourced) tropical hardwoods, woods treated with toxic chemicals, and non-renewable carbon-intensive materials such as plastic, aluminum, steel and concrete.
• How can the quality of Accoya be guaranteed? Accoya has thoroughly been tested for dimensional stability, durability, paint retention and in-ground conditions, Accoya is so reliable that for many years it has been – and continues to be – used by scientists as the benchmark against which other treatments and modifications are measured.
• Does the process penetrate into the middle of the board? Accoya wood is modified to its core. This means it is unlike any competitor wood products, which tend to receive surface level treatment.
• What benefits does Accoya acetylated wood have over unmodified wood? Virtually all wood preserving treatments today work by impregnating toxic chemicals (such as arsenic, oils, ammonia or metal compounds) into the cell walls of the wood. This works to fill the voids within the wood but this doesn’t change the underlying chemistry. The toxicity of such products also have negative environmental implications during the serviceable life of the wood as well as during its disposal.
• How is Accoya wood made? The Accoya production process does not weaken the original wood – in fact, its hardness is slightly improved and its bending strength uncompromised. Indeed, no modification process exists which offers the performance benefits and retained physical properties of Accoya.