What is Green Oak Timber?

What is Green Oak Timber?

What is Green Oak Timber?

Green oak timber is unseasoned ‘green’ oak, freshly cut within 3 to 18 months after the tree is felled, retaining high moisture content. Green oak frames are the primary structural element of a building, instead of steel or any other masonry, held together using pegged mortice, tenon, dovetail and other joints. The oak members can be infilled with other timber or brickwork to make it look as pleasing as possible. The timber can be beams, posts, braces or roof trusses.

What Settings Suit Green Oak Frames?

Many historical buildings were once oak framed, so people like to create that look and character because they look so good. Known for its robustness and distinctive character, green oak is a preferred choice for many heritage properties and bespoke new builds including garages, extensions, conservatory, garden rooms, entrance porch, barn, outbuildings and swimming pool structures that seek a rustic look coupled with modern architectural strength.

What are the Characteristics of Green Oak Frames?

By its very name, it is unseasoned, which means it has a high moisture content, usually about 20% to begin. It will reduce to about 12%, and maybe even further so you will get checking and splitting but this only characterises the wood further. Whilst green oak can be expensive it is cheaper than seasoned oak, as this type of wood is air dried or kiln dried which can be expensive, whereas green oak leverages the natural drying and hardening process of oak to enhance the structural integrity of the frame over time.

Benefits of Green Oak Framing

Choosing green oak framing offers several advantages:

  • Aesthetic Appeal: The natural beauty of oak enhances the visual appeal of buildings, providing a warm, organic look.
  • Sustainability: Oak is a renewable resource and using it in its green state minimises processing and energy consumption.
  • Durability: Oak is known for its strength and longevity, with many green oak frames lasting for centuries.

Timber stands out as an exceptionally sustainable material, primarily because it effectively reduces CO2 levels by absorbing carbon dioxide from the atmosphere. When harvested from sustainably managed forests, green oak timber is a genuinely renewable resource.

Any structural timber frame requires evaluation by a competent structural engineer. As oak dries, it becomes harder and stronger but may experience splitting, shrinking, or distortion. Joints should be designed to “tighten up” during this phase. Due to these unique characteristics, specialists must design the structure. For projects involving green oak frames, from residential homes to commercial buildings or historical restorations, our team provides expert timber structural engineering solutions.

If you are considering using green oak for your build and require detailed drawings, don’t hesitate to get in touch, you can call us on 01794 524447 or email

Why choose AWA Engineers

AWA is a structural engineering and civil engineering consultancy established in 1987, with a hard-won but deserved reputation for delivering excellence in our profession.

Our philosophy is simple: we put people first. This has resulted in a high number of repeat clients and an impressive track record of successful award-winning projects. We are proud to be professional, and approachable; we believe this makes us the ideal partner for your project.

AWA has chartered engineers in our offices located in Romsey, Hampshire and Bath, Somerset. We deliver services to clients across the South, South East and South West.

Our team includes both chartered structural engineers and chartered civil engineers committed to continuous professional development ensuring you benefit from up to date industry expertise, whatever your project entails.

Contact us today

To find out more about how AWA can help with your project, get in touch today. Call 01794 524447 (Romsey) or 01225 251498 (Bath)  to speak to a member of our team. Alternatively, email and one of the team will be in touch.

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