What moisture content should oak logs have?

The ideal moisture content for oak logs is between 10% and 15%. At this level, the wood lights easily, burns efficiently and delivers the maximum amount of heat from every log.

In the UK, any firewood sold as Ready to Burn must contain less than 20% moisture. At Logan's Logs we're proud to be Woodsure Ready to Burn certified, but we don't simply aim to come in under the legal limit. We dry our oak logs well below 20% because drier logs provide a cleaner, hotter and more enjoyable fire.

How moisture changes as oak dries

Growing Oak Tree

A living oak tree is full of water. Depending on the season and the part of the tree being measured, freshly growing oak can contain 50–70% moisture, sometimes even more. Much of the tree's weight is actually water rather than usable fuel.

Freshly Cut Oak

Immediately after felling, oak still contains a huge amount of moisture. At this stage it's known as green wood and is completely unsuitable for burning. A large proportion of the fire's energy would simply be wasted evaporating water instead of heating your home.

Seasoned Oak

Traditionally, oak was stacked outdoors and left to season naturally for two or three years. While this removes a significant amount of moisture, the final result depends entirely on the weather, airflow and storage conditions.

Well-seasoned oak may reach around 20–25% moisture, but in the UK's damp climate it often remains wetter than many people realise. That's why seasoned logs can sometimes be difficult to light and produce more smoke than expected.

Kiln Dried Oak

Kiln drying removes moisture under carefully controlled conditions, producing consistently dry logs that are ready to burn immediately.

Quality kiln dried oak typically has a moisture content of around 10–15%, allowing it to ignite more easily, burn hotter and leave your stove and chimney cleaner. Oak logs burn longer than other hardwoods and a lot longer than softwoods.

Why moisture matters

Every litre of water trapped inside a log has to be heated and boiled away before the wood can release its full energy. That means wetter logs produce less useful heat, more smoke and greater creosote deposits inside your flue.

This is especially important with oak. Oak is one of the densest hardwoods available and takes many decades to grow. It stores an enormous amount of energy, but you'll only benefit from that if the wood has been properly dried. Burning wet oak wastes much of the potential heat that nature spent years creating.

For the best performance, choose kiln dried oak with a moisture content around 10–15%. It will light more easily, burn longer, produce more heat and make the very best use of this premium hardwood.