Timber Care After Milling

Once your timber has been milled, the way it is stored and cared for will make a big difference to how well it dries, how much movement occurs, and how usable the timber is in the future.

Freshly milled timber contains a large amount of moisture. As it dries, the timber will naturally shrink, move, and sometimes split. This is normal, but good storage practices can help reduce waste and improve the final result.

Stacking Your Timber

After milling, slabs and boards should be stacked with thin pieces of timber, commonly called “stickers”, placed between each layer. These stickers create an air gap between the boards or slabs, allowing air to flow evenly around the timber. Good airflow helps the timber dry more consistently and reduces the risk of mould, staining, and uneven movement.

For best results:

Place stickers between every layer of timber.
Keep stickers lined up vertically above each other to avoid bending or warping.
Use dry, clean stickers where possible.
Keep the stack level and well supported.
Place weight on top of the stack if practical to help reduce movement.

Store Timber Under Cover

Timber should be stored out of direct weather, ideally under cover in a shed, carport, or similar sheltered area.

The storage area should protect the timber from rain and direct sun, while still allowing the stack to breathe. A closed-up space with no airflow can trap moisture and slow the drying process, while direct sun and wind can dry the timber too quickly and cause excessive splitting.

A good drying area is:

Under cover
Protected from rain
Out of harsh direct sunlight
Open enough to allow airflow
Off the ground
Level and stable

Avoid wrapping fresh timber tightly in plastic or storing it directly on the ground, as this can trap moisture and lead to mould or rot.

How Long Does Timber Take to Dry?

The rule of thumb for air-drying hardwood is approximately one year for every 25mm of board thickness. However, this varies significantly based on density, ambient humidity, and airflow. High-density Western Australian hardwoods like Jarrah and Marri often require patient drying periods to reach equilibrium moisture content.

Why Slow, Even Drying Matters

Timber dries from the outside in. If the outside of the timber dries much faster than the inside, stress can build up within the board or slab.

This can cause:

End splitting
Surface checking
Warping
Bowing
Twisting
Internal stress in the timber

The ends of slabs and boards often dry faster than the middle, which is why end splitting is common. To reduce this, some people seal the ends of their timber using paint, wax, or a dedicated end-grain sealer. This slows moisture loss from the ends and helps the timber dry more evenly.

End sealing does not stop all cracking, but it can help reduce unnecessary splitting and improve the usable length of the timber.

Can Timber Drying Be Sped Up?

Yes, drying can be sped up, but it needs to be done carefully.

One option is to create a simple dehumidifier kiln. This can be done by using a sealed space, such as a shipping container, and installing a dehumidifier to slowly remove moisture from the air.

For this to work effectively, the space needs to be reasonably airtight and have access to power. Fans can also help circulate air inside the container so the timber dries more evenly.

A basic dehumidifier kiln setup may include:

A sealed shipping container or enclosed room
A dehumidifier
Internal fans for air movement
Properly stacked timber with stickers between each layer
Monitoring of moisture levels over time

Drying timber too aggressively can still cause splitting, checking, and warping, so the aim is controlled drying rather than simply removing moisture as fast as possible.

Important Things to Remember

Seal end-grain immediately after milling to prevent rapid moisture loss and splitting.
Check the stack periodically for signs of pests or uneven movement.
Use a moisture meter to verify readiness before starting your project.
Be patient—the results are worth the wait.

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