Material matters

Discover the different types of oak and how they are suited for building

Green oak is the term for newly felled timber. It has high moisture content – between 60 and 80 per cent – which makes it easier to work with when carving, shaping and jointing the structural components. Green oak dries out over time, shrinking in the process, which strengthens the frame. It is important to work with an experienced supplier who understands how the oak will move over time, as this will need to be factored into the design of the frame. Green oak is cut to order, so using it minimises wastage.

Seasoned oak has been air dried, meaning it has a much lower moisture content, usually around 20 to 30 per cent. It is much more stable than green oak, so is less susceptible to moving and twisting, making it well suited for framing glazing or doorways, where movement needs to be minimal. It is also possible to use kiln-dried oak – this is where the drying process is accelerated via the use of a kiln.