Kiln dried firewood can be essential part of having fires in any wood burning fireplace or stove.
Kiln dried firewood can differ from other types of firewood such as seasoned firewood, and has a number of properties that can make it more useful for certain situations.
This article is a complete guide to kiln dried firewood, including what it is, what it does, the benefits of kiln dried firewood, how it compares to other types of firewood, and when and where you should be using it when having wood fires in your home.
What Is Kiln Dried Firewood?
Kiln dried firewood is wood that has been dried out within a kiln in order for the moisture content of the wood to be reduced to levels that makes it suitable for burning.
Freshly cut wood will be high in moisture content and so would be unusable as firewood because the fire would need to burn off the excess moisture before it could burn the wood effectively. In order for the wood to be used as firewood, it’s placed in a large oven-like atmosphere for a short period of time in order to evaporate off the excess moisture.
Drying out wood for use as firewood through kiln drying is a much faster process than conventional air drying (seasoning), and lower levels of moisture can be reached within the wood through kiln drying.
What Is Kiln Dried Firewood Used For?
Kiln dried firewood is a form of fuel used for burning in any form of wood burning fireplace, such as open fireplaces or wood burning stoves.
You can typically find kiln dried firewood in two forms:
- Kiln dried kindling
- Kiln dried logs
Kiln dried kindling is great for use at the start of a fire. Kiln dried firewood typically has very low moisture content , meaning that it can catch fire and burn very quickly, therefore helping a fire to get going as quickly and successfully as possible.
Kiln dried kindling can be split from kiln dried logs, or can simply be bought as a bag like the one we bought below:
Kiln dried logs are also great for when building a fire in order to help the fire catch as quickly as possible. They can also be used throughout a fire to help reduce any potential issues of wood that is too from causing the fire to struggle or go out.
Kiln dried logs can be ordered in bulk from a local supplier or bought in bags like the one we currently have:
Benefits Of Kiln Dried Firewood
The benefits of using kiln dried wood as your firewood include:
- The moisture content of the wood is typically lower than seasoned wood.
- There is less likelihood of buying wood that is still too wet to burn efficiently on a fire.
- Kiln dried wood can catch fire and burn much more quickly compared to seasoned firewood due to its generally lower moisture content.
- Kiln dried wood is therefore great for when starting fires because it can help the fire to get going as quickly as possible and reduce the chance for the fire to go out.
- As a result of typically lower moisture levels, kiln dried firewood can produce less smoke when burnt.
- Can produce a cleaner burn, leading to less creosote being produced, which can build up in your chimney or flue over time. Using kiln dried wood can therefore read to not needing to have your chimney swept as often if you burn wood regularly.
- The time it takes for wood to dry through kiln drying is far less than air drying, which can take anywhere from 6 months to 2 years.
- Kiln drying kills any insects and so you can store kiln dried wood in your home more safely.
- Kiln drying can also remove any other problems with the wood such as diseases.
- Kiln drying wood achieves the same low moisture content firewood each time. The ability for air dried firewood to reach low enough moisture content can rely wholly on how good the weather and climate is throughout the seasoning process.
Although there are many benefits to using kiln dried firewood, there are also some downsides:
- Kiln drying can cause the moisture to reach levels lower than what is recommended for efficient burning.
- Very dry wood can burn at a faster rate, leading to more wood needing to be added to the fire more often.
- Kiln dried firewood can be more expensive to buy than seasoned firewood because of the more involved process required to dry out the wood.
Kiln Dried Firewood Moisture Content
Kiln dried firewood should have a moisture content of less than 20% to allow it to burn efficiently when used on a fire.
Freshly cut ‘green’ wood will almost always be higher in moisture content than what is recommended for use as firewood. A number of factors, such as the time of year the wood is cut, will dictate the starting moisture level of the wood.
The Environmental Protection Agency (EPA) recommends that wood burns the most efficiently between 15 and 20% moisture content.
In order for the moisture level of green wood to be reduced to acceptable levels for use as firewood, the wood needs to be dried out. Along with air drying (seasoning), kiln drying is one of the processes that’s used to dry out wood for it to be used as firewood.
From testing the moisture content of our own kiln dried logs using a moisture meter, we’ve found kiln dried logs on average to be lower than 6% moisture content.
Our moisture meter is able to provide a moisture reading of down to 6%. When using our moisture meter to test our kiln dried logs, the meter couldn’t read any of the moisture readings, meaning that all of the logs were than 6% moisture content.
Comparing our kiln dried logs to our seasoned logs, the moisture level of our seasoned logs were shown to be higher than the kiln dried ones.
The moisture level of seasoned and kiln dried logs will always vary depending on many factors, including how long the wood has been dried for and the starting moisture content of the wood.
Seasoned logs will also always retain some sort of moisture level due to the humidity of the atmosphere. The moisture content of air dried wood therefore won’t drop below a certain level, no mater how long the wood is left to dry for.
On the other hand, firewood that is kiln dried is able to reach much lower moisture values than seasoned wood because the humidity of the atmosphere doesn’t play a role in the drying out process.
Kiln dried logs will therefore typically be able to reach lower moisture content levels compared to seasoned wood, and so kiln dried firewood can be a good investment if you’re struggling to get your fires going.
The moisture content of kiln dried firewood will very between each situation and so you’ll need to use a moisture meter to confirm what the actual moisture level of your particular kiln dried firewood is.
You can view our recommended moisture meters here.
How To Tell If Firewood Is Kiln Dried
Ways to tell if firewood is kiln dried include:
- It’s stated on the bag that the wood is kiln dried (if it comes in a bag).
- The wood has low moisture content level (checking by using a moisture), lower than seasoned firewood would be able to reach such as less than 10% moisture content.
- The wood can look less ‘weathered’ compared to seasoned logs that have been sitting outside for months or years.
- Light in weight.
- Can be splitting at the ends.
- Darker brown in color with no hints of green.
- The bark may be peeling away.
- Burns very well and fast in a fire.
Our kiln dried logs come in bags, and it’s clearly stated on the bags that these logs have been kiln dried rather than seasoned.
You can also use a moisture meter to check the moisture content of the wood to give an indication of whether it has been seasoned or kiln dried.
Kiln dried firewood can have a lower moisture content than what seasoned firewood will be able to reach.
Seasoned firewood typically won’t be able to get any lower then 10 or 15% moisture content, and so any logs with less than 10% are a sign that the firewood may have been kiln dried rather than air dried.
Differences Between Kiln Dried Wood and Other Types Of Firewood
We’ve explained above what a typical piece of kiln dried firewood could look like and what properties you’d expect it to have, but how does kiln dried firewood compare to other types of wood such a seasoned (air dried) firewood and freshly cut ‘green’ firewood?
The differences between kiln dried firewood and air dried firewood, are that seasoned firewood:
- Has been left out to dry for a much longer period of time and so can have more of a ‘weathered’ look to it.
- Will typically not have as low moisture content levels as kiln dried firewood because, due to the humidity of the atmosphere, the moisture will only reach a certain level before it won’t be able to dry out any more.
The differences between kiln dried firewood and green wood are that freshly cut wood:
- Has a green tint to it.
- The bark peels away in strands rather than in one go.
- Is visibly moist behind the bark.
- Is heavier than dry wood because of the extra moisture.
Is Kiln Dried Wood Better Than Seasoned Firewood?
In certain circumstances kiln dried firewood can be better than seasoned firewood.
The main property that kiln dried firewood has over seasoned firewood is that kiln dried firewood can be at lower moisture content levels than what can be achieved through air drying the wood.
A lower moisture level can help the firewood to catch fire more easily and burn with fewer potential issues. A downside of lower moisture content is that kiln dried firewood can burn at a faster rate, leading to more wood needing to be added to the fire more often.
Kiln dried firewood is therefore a great choice for use as both kindling and logs when building a fire and getting the fire going.
Wood that is too high in moisture is one of the main reasons why a fire can struggle to get going and keeps going out (we have a whole article that explains the main ways to help keep a fire going in your fireplace here). Using kiln dried wood is therefore a great way to help improve your fires if they’re struggling to get going once lit.
Once a fire has got going however, kiln dried wood becomes less useful. Its typically low moisture content will cause the wood too burn too quickly to be efficient.
Moisture levels of wood become less important once a fire has started because the hotter fire will be able to deal with wood that is higher in water content without it causing the fire to go out.
The recommended moisture content of wood for most efficient burning is between 15 and 20%. Within this range, firewood has a low enough moisture content that allows it to burn effectively in a fire without causing the fire to struggle. It also isn’t too low that it would cause the wood to burn too quickly for it to be an efficient source of heat.
To help prolong the length of time your pieces of wood are burning for you should aim to be adding logs that are between 15% and 20% once the fire has got going. You may find that seasoned wood becomes more useful throughout the remainder of your fires if you’re finding that your kiln dried wood is too dry and therefore burning too quickly.
You can use a moisture meter to read the exact moisture content of your wood.
For more information we have a complete guide to using a moisture meter to read the moisture content of your wood right here.
In summary, in many situations it’s best to:
- Use kiln dried logs and kiln dried kindling when building a fire to help get the fire going as quickly as possible.
- Use seasoned firewood once the fire is hot enough to sustain a longer burning and more efficient fire.
Is Kiln Dried Wood Worth It?
Kiln dried firewood is worth it if:
- You’re struggling to get your fires going.
- The wood that you’re buying isn’t properly seasoned to recommended moisture content levels.
- The draft on your stove or fireplace is poor and you need to help warm up the air within the chimney or flue more quickly.
- You want hotter burning fires.
Kiln Dried Firewood Issues And Solutions
Kiln Dried Wood Has Got Wet
Firewood doesn’t quite soak up water as much as you might think.
If kiln dried firewood gets wet, or is getting wet, simply leaving it outside under a suitable cover (such as inside a wood shed or under an overhang) for a couple of days will help to dry out the wood.
Wind plays an important role in drying out wood and so you’ll need to ensure that the wood is open to the atmosphere on at least one side.
Kiln dried firewood can absorb moisture over a long period of time if left outside uncovered. It’s therefore beneficial to keep your kiln dried firewood stored inside (a garage for example) or under an overhang if being stored outside to help keep the rain off.
Kiln Dried Wood Won’t Burn
One of the main causes of wood not burning properly is as a result of excess moisture within the wood.
Use a moisture meter to check the moisture content of the wood, as the wood may have been insufficiently dried or has got wet.
The moisture level of the firewood should be below 20% for it to burn efficiently in a fire. If the moisture level is showing above 20% then the wood should be left outside in a suitable atmosphere to allow it to air dry down to below 20%.
Kiln Dried Firewood
Can You Burn Kiln Dried Firewood In A Fireplace?
Kiln dried firewood can be burnt in any form of wood burning fireplace, whether it’s a traditional open fireplace or wood burning stove.
Kiln dried firewood is great for use as logs and kindling when building and starting a fire, as the typically low moisture content helps the wood to catch fire more easily and burn more quickly.
Can Kiln Dried Wood Be Stored Outside?
Kiln dried firewood can be stored outside as long as it’s kept under the right conditions.
The firewood should be kept in a wood shed or under an overhang to protect it from the rain and snow. It should be kept off the ground or placed on a dry platform such as a concrete base. The wood should also not be fully covered over and should be left open on at least one side to allow the sun and wind to keep the wood dry.
Does Kiln Dried Wood Burn Longer?
Kiln dried firewood can burn better but doesn’t necessarily mean it can burn for longer periods of time.
Kiln dried firewood can have very low moisture content meaning that it may burn faster because less energy is required to burn off the excess moisture within the wood.
If you’re looking for your wood to last longer in a fire, look to use seasoned hardwood logs that have a moisture content of between 15 and 20%, in which the wood burns the most efficiently with a balance between causing the fire to struggle and longevity of the wood in a fire.
How Wood Is Kiln Dried
Wood is placed in a kiln, which is essentially a large oven, for a certain period of time until the desired moisture content of the wood has been achieved. The right moisture content can be achieved in a matter of days rather than months or years when air drying firewood.
Kiln drying allows the temperature and humidity to be controlled and is a much faster process than air drying.
Is Kiln Dried Wood Better For The Environment?
Burning seasoned firewood can be better for the environment compared to burning kiln dried wood.
The kiln drying process requires a lot of energy to achieve wood that is useable as firewood, while air drying simply reduces the moisture content of the wood naturally over time.
It’s important that whatever firewood is burnt that it’s low enough in moisture content. Even though seasoned firewood can be better for the environment than kiln dried firewood, if the moisture content of the wood is too high when burnt it can lead to the wood burning highly inefficiently and producing more smoke.