Accoya & Thermowood



Accoya timber is ideal for windows, doors, cladding, decking structural and much more. For windows Accoya is highly recommended. It has extremely low thermal conductivity with a durability class 1. Accoya timber has been modified right through to the core and its non-toxic treatment process does not weaken the timber. It is safe for humans and pets. It hardness has improved and does not compromise its bending strength. With combined durability and stability Accoya timber can be an ideal species for structural projects around the world.


Sustainability features

  • Lasting 50 years above ground, 25 years in ground/freshwater - Class 1 durability, surpassing even teak - Virtually rot proof Icon
  • DIMENSIONALLY STABLE - Swelling and shrinkage reduced by 75% or more - Doors and windows open effortlessly year round - Paints and varnishes last 3 or 4 times longer, greatly reducing maintenance costs 
  • INSECT BARRIER - Indigestible to a wide range of insects, including termites - Greatly reduced vulnerability
  • CONSISTENT QUALITY THROUGHOUT - Consistent, measurable modification quality from surface to core - No need to apply chemical preservatives when cut or planed
  • RETAINED STRENGTH & HARDNESS- The process does not compromise the wood’s strength - Hardness is increased - High strength to weight ratio makes it suitable for challenging applications
  •  PERFECT FOR COATING - Improved stability means coatings last 3 to 4 times longer - Easier to coat, less preparation and sanding required
  • EXCELLENT FOR MACHINING - Easy to machine and process - No special tools are required Icon UV RESISTANT - Superior resistance to UV degradation when translucent coated - Natural appearance lasts longer - The ultimate substrate and coating life is increased
  • NATURALLY INSULATING - Offers improved insulation in comparison with commonly used wood species - Ideal for applications where energy conservation is important
  • NATURALLY BEAUTIFUL WOOD - Process does not compromise the wood’s natural beauty
  • NON-TOXIC & RECYCLABLE - Protects the environment from the harmful effects of common treatments - May be safely reused and recycled



We highly recommend our thermally treated timber, it is environmentally sustainable and natural.

Sourced from plantations in Finland. We have especially brought in a treated red Baltic timber that is environmentally friendly. It has a richness and consistency in colour.


Features of this timber include improved tolerance to weather conditions, resistance to fungi and decay.

Only high temperature and water vapour are used in the production process of thermowood. Thermo Wood does not harm nature. It can be safely discarded at the waste site or burned to produce energy. The timber itself has an improved tolerance of humidity fluctuations, improved resistance from fungi causing decay. (Even in ground use).  This product has a durability class 2#.


This timber is rich and consistent in color making it a popular choice for our clients.


See Thermo Wood Handbook-


It's the ultimate product in timber due to its environmental aspects and wide range of potential uses.

these include:



Moldings, Floors, Paneling, Furniture, Boards and Tabletops, Joinery, Stairs, Saunas



Cladding, Doors and Windows, Decking, Garden Furniture, Garden Structures, Noise Walls


Special Uses

Musical Instruments, Small Objects

What kind of surface treatment is required for outdoor use?

Thermowood can be used outside Cedar Windows recommends that you treat your timber to protect it from the effects of UV radiation and problems caused by moisture. If one wants to create a long lasting surface, paint provides a good solution. The timber should be primed first. (so the paint does not peel) 


How can the color fade be prevented?

If you wish to preserve the natural rich color, the timber should be first treated with a primer, then once or twice with a pigmented wood oil or wood stain.