An important aspect of having fires in any form of wood burning fireplace or stove is to be burning properly seasoned firewood only.
Seasoned firewood has certain properties that allow it to burn more efficiently in a fire, and helps to ensure that there are fewer issues with starting fires or keeping them burning for longer.
On the other hand, freshly cut ‘green’ wood will burn highly inefficiently in a fire, and so must be seasoned outside for an extended period of time to reduce the moisture content to acceptable levels.
Burning wet wood can cause a number of issues that include more smoke being produced, wood that is harder to light and harder to burn, and less overall heat being produced.
It’s therefore important to understand why burning only seasoned firewood is so important, and so we’ve put together this complete guide on seasoned firewood to explain what it is, why wood needs to be seasoned, how to tell whether firewood is seasoned, and more.
What Does Seasoned Firewood Mean?
Seasoned firewood is wood that has been left to dry for an extended period of time through a process known as seasoning in order for the wood to be low enough in moisture content to burn effectively on a fire.
Seasoned firewood is commonly bought and used in fireplaces and stoves as a form of fuel to provide heat to a home. Seasoned firewood helps to improve the efficiency and heat output when compared to burning wood that is higher in moisture content, commonly known as unseasoned or ‘green’ wood.
When buying firewood, whether it’s a bag of logs from your local store or a larger delivery from your local supplier, the seller will typically market the wood as being ‘seasoned’. This is used to indicate that the wood is ready to be used as firewood.
Does Firewood Need To Be Seasoned?
Firewood needs to be seasoned so that it has the right properties to burn efficiently on a fire; specifically low enough in moisture content for a fire to burn it without struggling.
For wood to burn effectively in a fireplace or stove it needs to be dried out through either the process of seasoning or kiln drying.
Freshly cut ‘green’ wood will burn highly ineffectively if used in a fire. Green wood will be difficult to catch fire, harder to burn and will lead to an overall unpleasant experience when having a fire in your home.
Green wood will burn poorly if used on a fire because of the amount of moisture that is contained in it. Newly cut logs will be very high in moisture content, and much higher for what is recommended for use a firewood.
Wet wood struggles to burn because more energy is required by the fire to burn off the excess moisture before the wood can be effectively combusted. The higher the amount of water content in the wood, the harder it will be for the fire to burn the wood.
As a result of incomplete combustion, burning wet wood can also lead to more smoke being produced, leading to potentially more creosote build up within the chimney or flue.
The moisture level of wood therefore needs to be lowered to acceptable levels in order for the wood to burn efficiently on a fire.
This can be achieved through a process known as seasoning, which is leaving the wood outside in a protective atmosphere to allow the wood to be air dried over time. The wind and sun will help to naturally dry out the wood over many months until the moisture content has lowered enough for it to be used as firewood.
The recommended moisture content for properly seasoned firewood is below 20%. Once this has been achieved, the wood will be able to catch fire much more easily and burn much more successfully when used on a fire.
For more information on why firewood needs to be seasoned, we have a whole article covering it here.
How To Tell If Firewood Is Seasoned
Seasoned firewood has a number of distinguishable properties that makes it different from when the wood was first cut.
The reduction in moisture content from green wood to seasoned firewood causes the wood to both look different and act different.
How to tell if firewood is seasoned:
- The bark can be peeling away, and removing the bark from seasoned logs shouldn’t be too difficult.
- The wood will be brown in color with no hint of green.
- No visible moisture present, especially under the bark.
- Can be cracking or rough looking at the ends.
- Can have a ‘weathered’ look to it because it has been left outside for many months or years.
- Will burn very well when used in a fire.
- Will have a low moisture continent value, typically below 20%.
So what does seasoned firewood look like? Below are some pictures of seasoned firewood logs that have.
For more information we have a more complete guide on how to tell if firewood is seasoned in another one of our articles here.
How Firewood Is Seasoned
Firewood is seasoned by leaving it outside for a prolonged length of time to allow the sun and wind to help naturally dry out the wood, while also ensuring that the wood isn’t subject to too much moisture, either from rain or snow, or from moisture in the ground.
In order for wood to be usable as firewood, the moisture content must be lowered through a process known as seasoning.
Seasoning is another name given to the process of air drying the wood.
Leaving wood outside to naturally dry out over time is a lengthy process. The time is takes for wood to reach acceptable moisture levels can be dictated by the starting moisture content of the wood, the climate and the type of wood, but the whole process can take anywhere from 6 months to two years.
To help ensure that firewood seasons as quickly as possible, the wood is:
- Left open to the atmosphere on at least one side to allow the sun and wind to help dry it out.
- Kept up off any moist ground to prevent the lower layers from rotting.
- Placed under a cover or an overhang to help keep the rain and snow off the wood.
Below is how we season our own firewood.
Our wood is stacked up against the back of our garage on a concrete platform, and is protected from the majority of the rain thanks to an overhang from the garage. One side of the stack is completely open allowing the wind and sun to help lower the moisture content of the wood over time.
For more information on how to season firewood we have a complete guide to seasoning your own firewood here.
Seasoned Firewood Moisture Content
Wood needs to be dry enough in order for it to burn efficiently, but what does the actual moisture content of seasoned firewood need to be in order for it to be useable as firewood?
Seasoned firewood should be below 20% moisture content, with the range of 15-20% moisture content being when wood burns the most effectively.
The Environmental Protection Agency recommends burning wood is most efficient when the moisture level of the wood is between 15 and 20%.
Within this moisture range, the firewood isn’t too wet that the fire struggles to burn it. The wood also isn’t too dry that it would burn too quickly to be an efficient source of heat. Wood should therefore be seasoned long enough for it to be under 20% moisture before it can be used effectively as firewood.
You can use a moisture meter to measure the moisture content of your firewood. A moisture meter provides an accurate reading of the actual moisture level of your wood so that you can be sure that you’re only burning properly seasoned firewood.
We have a whole article dedicated to how you can use a moisture meter to measure the moisture content of your firewood right here.
Benefits Of Seasoned Firewood
You’ll want to ensure that you’re always burning properly seasoned firewood in your fireplace or stove. The main benefits of seasoned firewood are:
- Seasoned firewood will catch fire quickly and burn more effectively, leading to fewer issues associated with getting your fires going and keeping them going.
- Less smoke can be produced by properly seasoned firewood compared to wood that is too wet. Smoke is a sign that the wood isn’t being properly combusted, and can be as a result of excess moisture in the wood. Burning unseasoned wood can also lead to more creosote (soot) being deposited within your chimney or flue over time.
- Seasoned firewood provides a cleaner burn, leading to fewer harmful particles being produced and released into the atmosphere.
- Can start the draft more quickly thanks to hotter air being produced earlier into the fire.
- Less moisture in the wood allows for a hotter burning fire.
Seasoned Firewood Vs Kiln Dried Firewood
Firewood can also be sold as ‘kiln dried’ rather than seasoned.
The process of seasoning firewood can take anywhere from 6 months to two years, and the length of time can depend on a number of factors including:
- The time of year the wood was cut.
- The moisture content of the wood when it was cut.
- The time of year the wood started the seasoning process.
- How well setup the wood is to be seasoned.
Kiln drying wood vastly speeds up the drying out process for firewood. Rather than being left outside to dry naturally, the wood is placed inside a large oven-like kiln over a number of days.
Whether you buy seasoned firewood or kin dried firewood, both will burn very effectively when used on a fire in your home.
The main differences between seasoned and kiln dried firewood are that that kiln dried firewood can typically be more expensive to buy than seasoned firewood because of the processes involved in drying the wood quickly.
Kiln dried firewood can also be found to be even lower in moisture content compared to seasoned firewood, meaning that it can burn hotter and faster.
We tested the moisture content of a bag of kiln dried firewood can compared it to the moisture content of some of our seasoned logs.
The moisture content of the kiln dried logs were found to be lower than what our moisture meter could read. The lowest moisture content our moisture meter can read is 6.8% meaning that these kiln dried logs had a moisture content of less than 6.8%.
This is compared to logs that have been seasoned and were shown to have a moisture content of around 10%.
Due to the humidity of the atmosphere the moisture level of seasoned firewood will only be able to reach a certain level. This moisture level will vary between location and climate but it means that seasoned firewood will never be able to be as what is possible through kiln drying firewood.
Kiln dried firewood is therefore great for use at the start of fires. The typically low moisture level of kiln dried firewood can be used to help get fires going when they’re really struggling and when moisture plays a more important role.
Once a fire has got going and got up to temperature, fires will be able to deal with more moisture in the wood and so seasoned firewood becomes the ideal type of firewood to use.
However, if kiln dried firewood is too dry it can lead to an inefficient fire because the wood can be burning too quickly for the fire to be sustainable.
For more information we have a complete guide to kiln dried firewood right here, including its benefits and when and where you would use it over seasoned firewood.
Seasoned Firewood vs Unseasoned Wood
There are a number of differences between seasoned firewood and unseasoned ‘green’ wood.
Unseasoned ‘green’ wood:
- Has a greenish tint to it while seasoned wood will be brown in color with little to no hints of green.
- Will have moisture clearly visible under the bark. Seasoned wood will have no visible moisture.
- Can have bark that peels away in strands. Seasoned wood will have bark that is either already coming off or can be peeled off with ease in one go.
- Will be higher in moisture content than seasoned firewood. It can be normal for freshly cut wood to have upwards of 50% moisture, while properly seasoned firewood will have under 20% moisture content.
- Heavier than seasoned firewood because of the added water content.
Here’s what you can expect a newly cut piece of wood to look like:
Best Way To Store Seasoned Firewood
The best way to store seasoned firewood is outside in a suitable environment that’s off any moist ground, open to the air and under a protective roof.
In order for seasoned firewood to retain its advantageous properties, it should be stored somewhere that’s going to keep it dry.
If you’ve already seasoned your own firewood using the correct methods then it can be beneficial to leave the wood in the same place until it’s needed.
By following the recommended procedures for seasoned firewood, including keeping it off any moist ground, ensuring that’s it located under some sort of protective roof or overhang, and allowing it to be open to the atmosphere on at least one side, then it can be fine to leave the wood stacked in the environment until it’s used on a fire.
In the same ways that it allows wood to season well, it also provides an environment for the wood to stay dry, and therefore stay useable as firewood.
If you’ve bought in your firewood then you keep it stored outside under these conditions, or if you don’t have the space outside you can leave it in a dry area of your home such as a garage.
The important thing is to keep seasoned firewood dry when storing it for later use. If seasoned firewood gets wet it can be left to dry for a couple of days and it will be fine again (we have another article discussing how rain can affect seasoned firewood here), but if seasoned firewood is left out in the rain for a prolonged period of time then the wood can start to go bad, and can therefore become unusable as firewood.
It’s also important to keep seasoned firewood off any moist ground because water can seep back up into the lower layers of logs can cause them to go bad.
It can also be beneficial to bring any seasoned firewood you’re intending to burn inside your home at least a day before burning it. This gives the wood a chance to fully dry out before being used on a fire, as well as get up to room temperature, which can help the wood to catch fire more easily.
We bring our own seasoned firewood inside our home a day before use and simply leave it inside a storage box.
How Long Does Seasoned Firewood Last?
If stored correctly and kept dry, seasoned firewood will last for many years.
Storing our seasoned firewood correctly allows us to burn logs that have been sat outside our home for five years or more.
Moisture is the biggest cause of seasoned firewood not lasting, because firewood that is in contact with rain or moisture from the ground can cause the wood to rot over time and become unusable as firewood.
Does Seasoned Firewood Burn Longer?
Seasoned firewood will burn longer compared unseasoned firewood because it has the right properties that allow the fire to be able to burn it without struggling, or burn it too fast that would cause it to be an inefficient source of heat.
Seasoned firewood has a low enough moisture content that allows it to burn well on a fire, but not too low that would cause it to burn so fast that it would lead to an inefficient fire that’s burning through the fuel too quickly.
Unseasoned ‘green’ wood will burn highly ineffectively on a fire. A fire needs to use more of its energy burn off the excess moisture content before the wood can be properly combusted, leading to a fire that’s struggling to keep going and can be producing more smoke as a result.
Therefore, for the longest burning fires look to use properly seasoned hardwood logs that are less than 20% moisture content.[We have a complete step by step guide on how to use your wood burning fireplace right here, which includes more information about which types of wood you should be using at what points during the fire in order to help your fires last longer.]
Seasoned Firewood Issues And Solutions
Seasoned Firewood Got Rained On
If your seasoned firewood logs are getting wet or have been rained on, simply leaving them in a dry, but open, location will allow them to dry out without any ongoing issues.
Once wood has been seasoned it won’t absorb moisture like a sponge and start rising in moisture content. Leaving seasoned firewood that has got rained on in a dry location, such as garage or outside under sufficient cover for a couple of drays will allow the wood to get back to it’s previous level of dryness.
Problems start occurring when firewood has been subject to prolonged periods of time in contact with moisture, such as leaving the wood out in the rain or left lying on moist ground.
Seasoned firewood that has been in constant contact with moisture can start to rot, at which point it becomes unusable as firewood.
Keeping your seasoned firewood as dry as possible will help to ensure that it will perform well in your fires, no matter how long is has been stored for.
Seasoned Firewood Not Burning Well
If your seasoned firewood isn’t burning well, check that the wood has been properly seasoned by using a moisture meter to see its moisture content value. Properly seasoned firewood should have a moisture level of less than 20% for it to burn effectively on a fire.
The biggest cause of seasoned firewood not burning well can be that it’s still too high in moisture content. Wood that is too wet will struggle to burn in a fire because more energy is required to burn off the excess moisture before the wood can be burnt properly.
The ideal moisture range for seasoned firewood should be between 15 and 20%, but should always be below 20% to ensure it burns efficiently in a fireplace or stove.
You can use a moisture meter to read the exact moisture content of your firewood.
If your seasoned firewood is shown to be over 20% then it’s likely that the wood hasn’t been properly seasoned.
Depending on how high the moisture value is, you’ll therefore need to leave the wood to season for a while longer or even leave it outside under the right conditions until the next burning season.
Moisture meters are an essential tool for any fireplace. You can see our recommended moisture meters right here.
There can be other issues as to why your seasoned firewood isn’t burning well. See one of our articles here that explains the ways to help keep a fire going in your open fireplace.
Are Dead Trees Seasoned Firewood?
Dead trees are not seasoned firewood. Wood must be air dried in the right conditions to allow it to dry out to become useable as firewood.
Dead wood subject to regular and prolonged contact with moisture will lead to wood that goes bad and starts to rot, rather than become seasoned firewood.
Does Seasoned Firewood Pop Or Sizzle?
Seasoned firewood is capable of making pops and sizzling noises, and you’re more likely to hear the pops and sizzles of seasoned firewood compared to burning unseasoned firewood.
When burning wet ‘green’ wood it will make more hissing noises that can drown out the noises of any pops and sizzles. This is the sound of excess moisture being forced out of the wood as it gets burnt off.
To experience the best popping and sizzling noises from your fireplace, look to burn properly seasoned softwood logs. Hardwood logs will typically pop at a slower rate compared to softwood logs.