Kiln Drying

Quality Kiln Drying

If you need hardwood timber of a consistent quality, stability and durability, then kiln-dried timber is probably the best option for your project.

Kiln drying is a procedure where timber moisture levels are dried down to a workable condition in a kiln. The moisture content in timber can have a dramatic effect on its performance, this means that if the timber is not dried in the correct way, the quality will not be high enough to make worktops, flooring etc. Kiln drying timber also kills fungi and insect infestations.

At WL West Timber we kiln our own stock, as well as offering a kiln drying timber service for our customers’ hardwood timber.

Why Kiln Dry?

When freshly cut, timber contains a great deal of water, for example oak when felled can contain around 65% water. This is split between ‘free water’ and ‘fibre saturated water’ or ‘bound water’. Free water exists in liquid form in the timber and can be relatively easily removed by air drying, evaporating the free water. At Fibre Saturation the moisture is bound into the fibre of the timber. At this point the timber is around the 26-28% moisture point and is ready to kiln.

By gently kilning we bring the moisture content down to 12% +/-2%. This generally is what the moisture content of most houses is. Items manufactured from timber at this moisture content should then remain stable and not split or deflect.

For flooring installed with underfloor heating, the moisture content needs to be brought down to 8% as the timber is in close proximity to the heat.

Kiln drying also sterilises the timber from any insects.

Kiln Drying Services at WL West Timber

We use two kilning technologies, circulated heated air and dehumidification kilns. The first uses circulated heated air, the timber is monitored for moisture content, and if the computer program sees the moisture content dropping too quickly it will inject small amounts of water, which steam and condition the timber slowing the process. Hot air is ejected from the chamber if the process gets too hot.

The dehumidifier uses refrigeration principles to evaporate the water away. It also circulates warm air in. This allows the timber to lose its moisture gently without compromising on the quality, structural integrity and appearance of the wood on completion of the kilning process.

Careful attention is given to how timber is stacked in the kiln, and the temperature and moisture content are checked at regular intervals throughout the kilning process. On average, the kiln drying process takes 3-4 weeks, until the wood has reached its correct moisture level for that species. The timber is then either stored in covered sheds or moved to our workshops, where we will plane, cut or leave the boards rough sawn according to your preference. We can arrange for delivery of your kiln-dried timber or you can collect your order from our Selham site as required.

Timber over 80mm in thickness is extremely difficult to kiln dry, so generally, 80mm timber is the thickest that you will find. Timber over this thickness will only be well air dried and normally down to around 18-26%.

Kiln drying services West Sussex

Key Benefits of Kiln Drying

  • After kiln drying, you will achieve a more uniform product with a consistent moisture content.

  • Kiln drying prevents the wood from warping, twisting or developing small cracks over time, thus improving stability.

  • The kilning process kills any pests, fungi or bacteria that might be in the timber. The reduction in moisture after kiln-drying also makes the timber significantly more durable, increasing its future resistance to fungal decay and wood-boring insects.

  • As kiln-dried wood has a lower moisture content, it weighs less than green or air-dried timber, which can lead to cost savings in transportation and make lifting and handling easier during construction/installation, ultimately saving time and effort.

  • Kiln-dried wood may still expand and contract with the seasons, but as it was installed at a stable moisture level, that expansion and contraction will have a very minimal effect.

  • Kiln-dried timber can be machined to a more superior finish than air-dried timber.

    It is also suitable for finishing immediately with a paint/stain, unlike fresh sawn timber.

Do you require a kiln drying service for your next project?

We are a well-established UK sawmill and timber merchant; supplying homeowners, trade & construction, heritage and restoration sectors.

With over 155 years’ experience, timber is what we do. Get in touch with our Sales Team for a quote or advice.