How Long Does it Take to Kiln Dry Wood?

Kiln drying wood is an integral step in the lumber industry, ensuring timber products attain the required moisture content for optimal performance and longevity. However, how long does it take to kiln dry wood? 

Initial Moisture Content and Wood Species Information

One of the key determinants of kiln drying time is the initial moisture content of wood. Freshly cut “green” wood contains up to 50% or more moisture when it is first cut. Therefore, with higher initial moisture contents it will take more time for wood to fully dry in its kiln.

Furthermore, the type of wood being dried also plays an integral role. Softwoods like pine and cedar typically dry faster than hardwoods like oak and maple due to differences in their cellular structures; softwoods generally have more porous surfaces for moisture removal.

Size and Thickness of Lumber

Size and thickness of lumber being dried have an impactful influence on its drying timeline. Thicker boards or larger pieces that retain moisture for extended periods will require extended drying times in order to reach uniform moisture content throughout. Proper stacking or arrangement in a kiln can help optimize airflow and drying efficiency, speeding up drying times. It is crucial to undestand sizing when it is comes to how to kiln dry wood. 

Kiln Type and Technology

Kiln type has a significant effect on the drying process. Traditional steam or dehumidification kilns employ different drying techniques and performance levels. Traditional ones may use high temperatures and controlled humidity levels to speed up drying while dehumidification kilns use lower temperatures with no humidity control to dry wood gradually.

Recent advancements in kiln technology have made for more efficient and environmentally-friendly drying methods. Vacuum kilns use reduced pressure to lower the boiling point of water for faster drying at lower temperatures; solar kilns harness solar power to dry wood naturally as part of an eco-friendly drying alternative to conventional techniques.

Balance Speed and Quality for Success

Although it can be tempting to speed up the drying process in order to meet production needs, quality must always take precedence over speed. Rushing the drying process may result in defects like warping, checking, and internal stresses which compromise its structural integrity and appearance, jeopardizing its integrity and appearance.

Patience and close monitoring are essential to the successful kiln drying experience. Woodworkers must strike a delicate balance between speed and quality in their drying, making adjustments as necessary to minimize defects while producing optimal outcomes

With the cost of lumber and hardwood in constant flux, it can be difficult to forecast how much a project might cost. Whatever the bottom line ends up, you will pay more for wood now than you would have just a few years prior. This means if you have your own hardwoods, it is far more beneficial to reclaim this timber and prepare it for personal use. To do this you will need to not only process it through a portable sawmill, but keep in mind you will also need to dry the wood.

The problem with not having your wood kiln dried is your woods moisture content to an acceptance level. When left to dry without the aid of a kiln, it will never be dried permanently, in other words non kiln dried wood can still receive moisture and bugs/microorganisms that reside in wood and could remaining active.  However, dry times in a kiln  are not universal, and there are several elements to consider.

Variables in Kiln Drying

You might initially consider drying the wood out naturally to cut down on the price of processing your timber. We recommend not going this route. Why? Because it can take wood upwards of one year per inch of thickness for the wood to dry to the proper moisture content(it might even take longer than this if the wood is left in a humid space). This air dried wood is not suitable for fine furniture, flooring and really any wood used inside. Thankfully, drying wood with a kiln will dramatically reduce the dry time, protecting your current and future investment. 

There are different kinds of kilns to consider. First, there is the regular kiln that uses heat to dry the wood, and nothing more. This kiln does take the longest to dry your wood. The next option is a dehumidifier kiln. Tennessee can be a humid place, and that humidity will affect how long it takes to dry your wood. With a dehumidifier kiln, you’ll not only have the heat of the kiln, but the dehumidifier will pull moisture out of the air, which in turn helps the wood dry faster.

Last, there is the vacuum kiln. This will reduce the dry time of your wood the greatest. This is because the vacuum feature will help extract moisture directly from the wood. Combined with the kiln’s heat and you will slash dry time as much as possible.

The species of wood you’re drying will also play a role in how long it takes to dry. Thicker, denser wood, as you might have guessed, will take longer to dry. On the other hand, softer wood will dry faster. Cherr, for example, dries quickly. and other fruit trees might take about twice as long as cherry, but still, these will dry quickly. On the other hand, oak, as well as hickory, can take significantly longer to dry due to their moisture content.

Benefits of Kiln Dried Wood

Perhaps you don’t mind waiting for the wood to dry naturally. You are still in the early phases of planning a project, and, in reality, you have at least a year before you’ll be ready to use the wood. If that sounds like the situation you are in, and if you have space to store the wood to dry, you may be considering going this route. However, beyond reducing the dry time, there are several other benefits of kiln-dried wood.

First, using a kiln to dry your wood will kill off all the insects, bugs, eggs, and other undesirable organic material that is in the wood. Air drying the wood will not do this, which means if you’re not careful, the air-drying wood may manifest a large amount of wood-consuming insects. Taking advantage of the kiln drying option will also harden any resin remaining on the wood. Without a kiln, the resin will remain in a liquid state, which is not desirable. Dried resin can have a beautiful look, while wet resin doesn’t have any benefits.

To kill off insects and to prepare the wood for air drying, you might be forced to use a topical chemical on top of the wood. The chemicals can deteriorate the quality of the wood, and even so, you’ll never extract the same amount of moisture from the wood as you would with a kiln. With all of the available benefits, you’re simply better off going with a kiln to dry your wood.

iDry Kilns

The Bloodhound crew uses the iDry Kilns to kiln dry all of our hardwoods. These kilns are state-of-the-art vacuum kilns that effectively dry your hardwoods in the shortest amount of time possible. The stainless steel vacuum chambers used for your wood allow you to have usable wood in as little as a few weeks (if not several months).

We like this kiln so much that we purchased 2! Have wood to dry? The Bloodhound crew can help!

What is keeping you from getting started?

 If you have trees you want to transform into usable lumber, you will need to mill the wood and then dry the wood – preferably through a kiln. Whether you are interested in using the wood yourself or you’re interested to know the best ways to store kiln dried wood, we are here for you. Whatever questions you might have, they can be answered by contacting a member of the Bloodhound crew. Contact us today.