Understanding Movement in Oak

Understanding Why:

Movement in oak happens when the humidity in the local environment differs from the moisture content within the timber. High humidity causes the wood to absorb moisture and expand, while low humidity leads to drying, causing shrinkage or even splitting.


Several factors contribute to this humidity/moisture imbalance, with common culprits being:

  1. Incorrect Initial Moisture Levels: The timber used might have had an inappropriate moisture content from the start.
  2. Inadequate or Untimely Application of Finish: The finish applied may not be suitable, or it might have been applied poorly or too late.
  3. Varied Weather Conditions: Unavoidable, yet manageable by addressing the first two factors effectively.


There are a few things that it is important to consider when buying oak, that will reduce the impact of the natural movement of oak in your building project:

  1. Thorough Application Awareness:

Ensuring that everyone involved has a comprehensive understanding of the project details, such as location, sun and rain exposure and heating plans, will mean that the right materials can be selected in order to minimise the movement of the oak.

  1. Communication:

If everyone, most importantly the end user, is correctly educated about the properties of oak, the effects of changing weather, areas at the highest risk of movement and the steps in place to minimise the movement of the oak then that will remove the risk of an unsatisfactory outcome.

It is vital that the client fully understands the nature of the product and the way it behaves before they purchase the goods.

  1. Timber Selection:

Choosing the right timber is very important in minimising the movement of oak. Our team of experts are always happy to help make the right choices. It is important to consider unique situations, like a south-facing front door in a well heated home – it’s easier to ask the experts and get the right product in the first place than choose the wrong product and end up with problems!

  1. Build Tolerances:

Accounting for seasonal movement without compromising joint integrity is just a part of what we do, but not everyone thinks about it. Discussing this with our team can save a headache later on, by predicting the behaviour of the oak as it settles in to its new surroundings and allowing for this in all buying decisions.

  1. Quality Finish Application:

Choosing a quality and recommended finish, such as Osmo UV Protection Oil for external use or Osmo Polyx Oil for internal use, and applying it thoroughly before installation can be a key (and often overlooked) step in the protection of oak.

  1. Precision in Fitting:

Using the appropriate fixings, ensuring they are long, strong, and resistant to moisture, will ensure that the movement of the oak is managed effectively. Identifying critical anchor points and allowing for movement where possible will also be critical.

  1. Celebrate Success:

You can now rest easy knowing that by following these steps, you have minimized the risk of issues related to wood movement!