Accoya

Unbeatable Performance, Finish, and Sustainability

Accoya^® is 100% solid wood that is modified to the core using a non-toxic proprietary acetylation process. When your customers demand a superior product, Accoya^® will answer all their needs. It is ideal for a range of applications, including siding, facades, shutters, decking for residential marina boardwalks and public parks, window casements or patio doors, and custom projects limited only by your imagination.

A New Way of Thinking About Wood

Accoya^® not only delivers unmatched durability and textural finishes that look brilliant and last longer—it is sourced from responsibly managed forests. The benefits of Accoya® mean that timber projects can now be designed with absolute confidence. Accoya^® lumber is warranted against rot and decay for 50-years above ground, and 25-years in-ground with freshwater contact. Our quality mark signals the Accoya^® difference.

Please send us your quotes and inquiries to get started.

Wood that stays true

Accoya remains structurally sound with virtually no movement before, during and decades after the job is complete.

High usability with boards that stay straight before and after installation.
So dimensionally stable that even harsh environments will not impact installation.
3-4 times less swelling than traditional wood species, minimal movement keeps this project looking great.

Wood that’s guaranteed to last

Accoya solves the problem of deterioration in any climate, giving you the confidence that you made the right choice.

50-YEAR warranty above ground; 25-YEAR warranty in ground or fresh water.
Certified for use in termite zones and 22 times more resistant than pine, it’s exceptionally durable.
60-YEAR service life demonstrating significantly higher durability with real world testing.

Wood to change the world

Accoya has the environmental credentials to make a bold commitment to build any project sustainably.

Peace of mind with the knowledge that all Accoya comes from FSC® certified forests.
One of the few building materials certified Cradle to Cradle® at the Gold level.
Non toxic and 100% recyclable.

Wood without compromise

Accoya is the ultimate workable substrate trusted by craftsmen to deliver in any product application.

Excellent machinability, easy to work with, no special tools required.
The best of both worlds, improved density and hardness without sacrificing strength.
Leave natural for exquisite grain patterns or create a unique finish of your choice.

In-House Accoya and Accoya ColorGrooving to fit Grad System

As an Official Grad® Milling Partner, Rex Lumber is proud to offer our customers our unique in-house capability of grooving Accoya® and Accoya Color® lumber for mouldings, decking, and siding to fit Grad system.

By pairing premium Accoya and Accoya Color products with in-house millwork expertise, Rex Lumber helps customers move seamlessly from concept to cut list. The result is a collaborative, efficient process that supports complex designs, reduces downstream challenges, and delivers wood components built to perform for decades.

Learn more about Rex Lumber’s custom millwork capabilities.

Custom Millwork for Accoya and Accoya Color

Rex Lumber’s custom millwork capabilities allow our customers to unlock the full potential of Accoya® and Accoya Color® for exterior and interior applications.

Grad System Logo Accoya performs best when precision milling and thoughtful fabrication are part of the process. Our in-house millwork teams work closely with customers early in project planning to ensure profiles, tolerances, and finishes are optimized for both performance and design intent.

Custom millwork capabilities for Accoya and Accoya Color include:

In-house Grad® grooving for decking and siding
Mouldings with Grad® grooves. 
Custom moulding profiles and trim packages
Precision milling for siding, cladding, and rainscreen systems
Machining for decking, screen systems, and architectural details
Consistent profiling that preserves material performance and appearance

Tongue and Groove Stacked Rex Lumber supports a wide range of custom Accoya® applications, from mouldings and trim to siding and cladding, decking, and architectural details. The wood’s predictable movement and rot resistance make it ideal for intricate profiles and tight tolerances, especially in exterior environments where consistency matters most. Our millwork capabilities help ensure clean lines, accurate reveals, and long-term performance in demanding climates.

Accoya Color® adds another layer of opportunity, combining the proven benefits of Accoya with factory-applied, through-body color. Rex Lumber’s custom millwork services allow Accoya Color products to be machined, profiled, and fabricated without sacrificing color consistency or durability. This makes Accoya Color an ideal choice for projects that demand a modern aesthetic, reduced finishing requirements, and long-lasting visual uniformity.

No Rot or Decay for50 Years!

Accoya^® is 100% solid wood; that is modified to the core using a non-toxic proprietary acetylation process.

Accoya^® lumber is warranted against rot and decay for 50 years above ground, and 25 years in-ground/fresh water contact. The heartwood and sapwood are easily distinguished. The texture is typically fine to medium.

Benefits of Acetylated WoodWhat is Acetylation?

acetylation wood technology Rather than spin tales of hydroxyls, hydrogen atoms and other chemistry jargon, in the simplest terms we can muster (in the context of Accoya lumber technology) acetylation is: subjecting a softwood to a vinegar, which turns it into a hardwood by preventing the cells in the wood from being able to absorb water.

So acetylated wood is… Pickled wood?

More or less. Yes.

Okay, the chemistry behind this is a little complex, and the vinegar is acetic anhydride. Not quite the malt vinegar for your fish and chips. But the principle is there.

Not at all. Don’t let the chemical name scare you. As sodium chloride is actually salt or dihydrogen monoxide is water. Nobody has come up with a sexy name for this vinegar yet. But importantly the reactive organic components are carbon, oxygen and hydrogen. So it’s not toxic at all.

The benefits of using acetylated wood.

When making anything out of wood, water is a main troublemaker.

Keep wood dry and well maintained and it’s one of the greatest materials of all time. But introduce water? Problems begin to seep in. With untreated, badly treated or unmodified wood, water can bring a whole host of problems including rotting, warping, splintering, swelling, shrinking and being food for hungry insects.

Acetylation wood technology removes the issue at source and is modified to the core, rather than treating wood with a toxic chemical trying to stop rot or insect attacks and not helping with other water issues. The result is real wood that doesn’t rot. It will hardly warp, swell or shrink. It doesn’t splinter and it isn’t termite chow.

What does Modified to the Core mean?

Accoya lumber is modified to its core, meaning it is unlike other treated wood products, which tend to receive surface-level treatment.

Accoya consumers can have total confidence in its durability not possible with traditional lumber. When Accoya is cut or jointed, there are no exposed unacetylated surfaces in any dimension of Accoya.

UnbeatablePerformance

Enjoy the peace of mind that comes from knowing your project will last for decades.

Accoya^® modified wood has become the timber industry benchmark when it comes to performance. Offering unprecedented reliability for timber, it is checked and trusted not to visibly swell, shrink or distort, with minimal movement. It is also highly resistant to insect attacks and damage. Highly durable and stable, it withstands the test of any climate. What’s more, it stays that way. A 50-year above ground, and 25-year below ground and freshwater warranty are testament to the fact that you can expect to enjoy your Accoya^® lumber for many decades to come.

Learn more about Accoya wood warranty. Download warranty info here.

The PerfectFinish

Building with wood is no longer a dance between design and practicality – you can achieve the beautiful finish you desire, without performance compromise or damaging environmental impact.

Why do architects and manufacturers love working with Accoya^®? The coatings look brilliant and last longer. In addition, easy and hassle-free care saves time and money in the long run. Accoya^® lumber also offers huge design freedom and the ability to apply a range of textural finishes such as smooth, charred and brushed, plus custom size and finish options for ultimate creative freedom.

ResponsibleSustainability

Accoya^® uses timber from forests that are proven managed in a way that is environmentally appropriate, socially beneficial, and economically viable manner. Stock that is FSC^® Certified is readily available.

Accoya^® lumber is the truly sustainable choice that helps you meet global challenges like climate change. From source to production and through to end of life, sustainability shines through. You can feel good knowing that at every single stage of its life, Accoya^® has minimal environmental impact.

FSC^® certified means that the wood is sourced from a forest that is responsibly managed. Trees in the certified forests are grown and harvested according to a strict set of guidelines that benefit the environment. These guidelines include:

Limiting the number of trees cut down
Restricting highly hazardous pesticides
Protecting indigenous people as well as wildlife habitats

Stock that is accredited by the FSC^® and Cradle to Cradle Gold certified™, it is the only construction material in the world to achieve C2C Platinum certification™ for Material Health. With a low carbon footprint, you can help combat carbon emissions for a healthier world. It’s also non-toxic, so safe for people and pets as well as the planet.

DistinguishedCharacteristics

Accoya^® is currently sourced and treated in Europe and then imported to North America. It is a modified softwood with heartwood and sapwood that are easily distinguished, and a texture that is typically fine to medium.

Accoya^® lumber works very well with almost all tooling, although care is needed when gluing and should adhere to the manufacturer’s guidelines. Due to the acidic nature of the treatment process, any metal in contact with Accoya^® (including fasteners) needs to be stainless steel or marine grade brass.

Accoya DeckingDurable Decking that Delivers Beautifully

Accoya^® Color Grey Decking combines the beauty of natural, sustainable wood with the advanced performance of an enhanced material to create the ultimate decking solution for outside living spaces.

Colored through completely from surface to core, the gorgeous Accoya Decking delivers a premium look that fits almost any style. Thanks to its patented design and finishing process, Accoya^® Color Grey is low maintenance and insect resistant with no coatings needed. It’s also barefoot friendly. Accoya^® Color Grey is sustainably sourced and non-toxic.

Accoya Decking Availability:

Size: 5/4 x 6″
Finished Deck Profile: 1″ x 5 3/4″
Lengths: 8ft, 12ft, 16ft

Learn More about Accoya^® Decking

Flawless, DurableAccoya Siding

Rex Lumber knows that aesthetics, low maintenance and durability are crucial. Your exterior wood siding needs to weather any storm, in style. What you may not know is that Accoya out-performs even the most durable tropical hardwood siding.

Featuring exceptional stability and minimal shrinkage or swelling, Accoya wood siding and cladding is an excellent choice for both modern architectural builds, and historic renovations. Accoya accepts paints and stains exceptionally well.

By combining superior stability and durability with the beauty of natural wood, you can achieve the look and the performance you want from your wood siding. Not to mention Accoya’s world-leading sustainability credentials.

To specify wood siding from Accoya in your next project, reach out and request a quote to get started today.

Accoya wood siding and cladding installation tips

Check out the Accoya Siding Guidelines for more information and tips on installing Accoya wood siding.

Accoya Siding Availability:

Size: 11/16 x 5-3/4″
Shiplap & T&G, 3/4 x 5-3/4”
Shiplap & T&G – custom sizing and profiles also available
Lengths: 8ft, 10ft, 12ft, 14ft, 16ft

Learn More about Accoya^® Siding

Accoya Sidingand Cladding Performance

Accoya siding is made of FSC® certified wood and has numerous advantages: lasting performance, beautiful aesthetic and the clear conscience that you have used a sustainable material.

Warranty

Accoya wood has an industry-leading warranty, giving you peace of mind and complete confidence for your beautiful wood siding.

Highly Durable

With wide boards, versatile surface texturing options through sawing, brushing, and charring, and a broad range of coatings, Accoya offers complete creative flexibility with no compromise on performance.

Highly Stable

Resistant to rotting, Accoya siding is likely to stay free of any visible distortion over its lifetime. A cost-effective choice for lasting performance.

Sustainably Sourced

Now you can meet the most demanding of planning requirements. Accoya wood siding is 100% non toxic and contains no biocides or harmful chemicals. Each siding panel is made from FSC® certified timber that’s fully sustainable.

Accoya Siding Performance Chart

For more information on Accoya wood siding and cladding performance, download the Accoya Performance Testing Brochure.

Accoya Wood Siding Applications

Accoya siding is very versatile, discover some additional uses here.

Charred Siding

Enhanced grain burnt to perfection. Accoya Charred Wood Siding boasts outstanding stability.

Color Grey

Accoya grey siding delivers lasting performance and contemporary style for any project.

Rainscreen Siding

The ultimate substrate for rainscreen siding, offering protection with style and substance.

Brise Soleil

Care and maintenance made easy. Accoya’s extreme machinability can accomplish any Architect’s vision.

AccoyaWooden Windows

Accoya wood windows combine the natural beauty of real wood with exceptional stability that resists shrinkage, swelling, and rot. Engineered for outstanding performance, sustainability, and low maintenance, Accoya is backed by a 50-year warranty.

Benefit from long-lasting wood windows that maximise beauty and require minimal upkeep.

High Performance Wood Windows

Quality where it counts

From its superior insulation to its lasting good looks, Accoya wooden window frames outperform other woods and uPVC in every way. Not to mention being better for the environment and healthier for you. Whether you’re looking for traditional wooden sash windows, stylish bay windows, practical casement windows or impressive architectural glazing – Accoya delivers on all fronts.

Accoya wood window performance

Accoya high performance wood windows out-perform traditional hardwoods and in many cases, uPVC and aluminum.

50 Year Warranty

Our outstanding 50-year above ground warranty is here to give you complete confidence that your Accoya wood windows will stand the test of time.

Low Maintenance

Accoya wooden window frames deliver all the beauty of natural wood with none of the downsides. That means minimal upkeep and maximum beauty.

Highly Stable

Wood windows made from Accoya are highly stable and have shown improved coating lifetime performance with many types of coatings, resulting in extended maintenance intervals.

Highly Durable

Highly durable & naturally insulating, you can lock in the warmth and lock down the price of your energy bills with Accoya wood windows. All while saving time, money and hassle on maintenance.

Accoya Window Performance Chart

Accoya Sash Windows

Classic look, contemporary performance. Add more character to your home or simply replace old or rotten old wooden sash windows.

Wood Casement Windows

Maximum light and all the benefits of real wood, without the drawbacks. Accoya casement windows are durable, stable and sustainable.

Accoya Bay Windows

Add that extra touch.
From simple to complex designs, Accoya bay windows allow you to enjoy panoramic views for years to come.

Accoya Shutters & Blinds

Accoya timber window shutters or blinds offer low-maintenance energy efficiency, working as effective controls on the solar energy.

For more information on Accoya wood window performance, download the Accoya Performance Testing Brochure.

Accoya Doors

A wooden door can be the face of a home, so it’s important to choose a door design that resonates with both the style of house and the homeowner’s personality. Accoya wood doors combine natural beauty with exceptional durability and stability, offering a sustainable, high-performance solution that stands the test of time in any climate.

External Wooden Doors

Durable wood doors that exceed all expectations

External wood doors protect your home from the elements, so choosing one that’s built to last is essential. Accoya wood doors are designed for lasting performance, delivering exceptional strength and resilience compared to traditional timber.

They also offer excellent thermal insulation and superior stability, meaning less shrinking, swelling, and maintenance over time.

Improved ThermalPerformance

Thermal value is a critical aspect in window and door design.

In comparison to other standard wood types for joinery, Accoya thermal conductivity is:

Superior to softwood by 8%
Superior to hardwood by 30%

Choosing Accoya wood for the construction of windows and doors will have a significant positive effect on the total thermal performance and therefore the energy balance of your home.

Accoya wood door performance

Accoya high performance wooden doors out-perform traditional hardwoods and in many cases, PVC and aluminium.

Long Lasting

Solid wood doors with long lasting performance – giving you the beauty of wood combined with peace of mind for your property.

Dimensionally Stable

Highly stable so harsh environments will not impact installation ensuring that your door’s performance stays true and coatings last longer.

Natural Wood

Accoya is real wood, but its excellent stability and durability outperforms even traditional hardwood front doors, such as oak.

Low Maintenance

With 3-4 times less swelling than traditonal wood species, Accoya’s minimal movement keeps projects looking great saving time and money in the long run.

Accoya Door Performance Chart

For more information on Accoya wood door performance, download the Accoya Performance Testing Brochure.

Accoya LumberAvailability

4/4 A1 – “4 Sides Primarily Clear” Rough Dimension
4/4 A2 – “3 Sides Primarily Clear” Rough Dimension
5/4 A1 – “4 Sides Primarily Clear” Rough Dimension
5/4 A2 – “3 Sides Primarily Clear” Rough Dimension
6/4 A1 – “4 Sides Primarily Clear” Rough Dimension
6/4 A2 – “3 Sides Primarily Clear” Rough Dimension
8/4 A1 – “4 Sides Primarily Clear” Rough Dimension
8/4 A2 – “3 Sides Primarily Clear” Rough Dimension
10/4 A1 – “4 Sides Primarily Clear” Rough Dimension
10/4 A2 – “3 Sides Primarily Clear” Rough Dimension
12/4 A1 – “4 Sides Primarily Clear” Rough Dimension
12/4 A2 – “3 Sides Primarily Clear” Rough Dimension
16/4 A1 – “4 Sides Primarily Clear” Rough Dimension