Wood needs to be dried out before it can be used efficiently as firewood. Drying out firewood can be achieved through the seasoning process, which helps to naturally lower the moisture content of wood over time.
The seasoning process for firewood can be lengthy, and so how long should firewood be seasoned before burning?
The time it takes for firewood to season can take anywhere from 6 months to 2 years, depending on a number of variables such as the starting moisture content of the wood, how well the wood is stacked and covered, and the climate. Firewood should be seasoned for at least 6 months before checking its moisture content.
We’ve discussed how long firewood should be seasoned for in more detail in the rest of this article, as well as explaining what affects how quickly wood seasons and how you can speed up your seasoning process.
How Long Should Firewood Be Seasoned?
In order for wood to burn effectively on a fire it must be dried out to sufficiently low moisture levels.
The main method for drying out your own firewood is through the seasoning process, where wood is left outside to dry out naturally over an extended period of time.
The time it takes for wood to fully season (dry out to recommended moisture levels) can vary between each situation, and there are a number of factors that can influence how long the seasoning process takes.
These factors can include the:
- Species of tree.
- Time of year the wood is cut.
- Starting moisture content of the wood.
- Time of year the seasoning process starts.
- How well the firewood is stacked.
- Whether the firewood is properly covered over.
- How well the firewood is left open to the atmosphere and the weather.
- Whether the wood is stacked off the ground or placed on a dry platform.
- Weather throughout the seasoning process.
All of the above factors can contribute to how long it takes for wood to reach low enough moisture levels that It will burn efficiently in your fires.
Type Of Wood
The type of wood can dictate both the starting moisture content of wood and how long the seasoning process can take.
Hardwoods from deciduous trees, such as Oak or Ash, can typically take a longer period of time to dry out than softwood logs from evergreen trees, such as Pine.
Deciduous trees can take longer to grow than coniferous trees, and this leads to logs that are typically denser. Denser hardwood logs can therefore take a longer time to dry out compared to less dense softwood logs.
Softwood logs being seasoned under the right conditions can dry out after 6 months.
Hardwood logs being seasoned under the right conditions can dry out to recommended moisture levels within a year.
Although hardwood logs can take a longer time to fully season, they have a number of benefits over softwood logs when used as firewood. As hardwood logs can be denser, they can:
- Last longer on a fire.
- Produce more heat from each log burnt.
- Produce a cleaner burn leading to less smoke being produced and less creosote being deposited.
Time Of Year Wood Is Cut
Natural moisture content levels of wood will vary throughout the year. Moisture levels will be higher during the spring and summer seasons and be lower during the winter months.
The starting moisture content of wood will play a role in how long it takes for the wood to dry out. The higher the starting moisture level, the further the wood is away from recommended moisture levels for firewood, and the longer it will take for the wood to dry out.
It’s therefore preferable to cut wood during winter when moisture levels are at their lowest, and start the seasoning process in early spring.
The moisture content of ‘green’ wood can differ between species. We cut a branch from one of the deciduous trees on our property in late winter and tested its moisture content with our moisture meter.
The moisture reading for this particular piece of wood was 35%.
We also cut a piece of wood from the same tree in early spring and the moisture reading for this piece of wood showed 45%.
The Environmental Protection Agency recommends that firewood burns best at between 15% and 20% moisture content.
The piece of wood with the lower stating moisture content would therefore have taken less time to season compared to the piece of wood with the 10% higher moisture content. This could have added a couple of months to the seasoning process before the wetter wood would have been dry enough to use as firewood.
As the length of time required to season firewood varies between each situation, using a moisture meter is the best way to keep track of how well your wood is drying.
We’d highly recommend getting a moisture meter if you don’t already have one. It will allow you to understand how well your firewood is seasoning and will help to ensure that you’re only burning properly seasoned logs.
How Well Setup The Firewood Is To Be Seasoned
Another aspect of how long firewood should be seasoned for is how well it has been setup.
In order for wood to dry out effectively, at least one side of the stack should be left open to the atmosphere.
The key players that progress seasoning of the wood are the sun and the wind. By leaving one side of the wood stack open it allows the wind to dry out the wood throughout the year, even in winter, and the sun to help dry the wood more quickly during the summer months.
Here’s how we season our firewood:
We season our firewood stacked up against the back of our garage, which allows the wood to get the sun and the wind all year round.
Our firewood is also placed in a concrete platform. This helps to prevent moisture from the ground from seeping back up into the lower layers of logs.
Placing your wood off the ground or on a dry platform will help the wood to season and prevent it from going bad.
Seasoning firewood should also be placed under a form of cover to help protect it from the majority of rain and snow. Our firewood is covered thanks to an overhang from the adjacent structure.
You can also use a sheet of tarpaulin to help cover your wood for seasoning, but the stack must not be fully covered and should remain open on one side.
Can Firewood Be Seasoned For Too Long?
Due to the humidity of the atmosphere firewood will always retain some level of moisture and therefore can’t be overseasoned.
Firewood can’t be seasoned for too long and simply leaving firewood in the same place for a longer period of time once it has fully seasoned won’t bring down the moisture content any further.
Once firewood has properly seasoned down to it’s lowest moisture content level then it won’t dry out any further, and can simply remain where it is as storage.
If firewood is seasoned for too long in the wrong conditions then it can cause the wood to go bad and rot rather than remain well-seasoned firewood.
If firewood is left seasoning for a longer period of time then it’s important to ensure that the wood remains dry. Constant contact with moisture will cause the wood to become unusable for use as firewood.
To help keep firewood dry during the seasoning process and to remain dry once the wood has been seasoned and left in place:
- Keep the wood raised off any moist ground or placed on a dry platform.
- Leave at least one side of the stack open to the weather elements.
- Place the logs under some sort of cover such as an overhang.