Last updated on December 6th, 2021
Our site is reader supported, this means we may earn a small commission from Amazon and other affiliates when you buy through links on our site.
When it comes to burning wood in a wood-burning stove or open fire, it is essential that you only use what is known as seasoned wood. Seasoned logs have a low moisture content, which means the fire burns efficiently, and with dry firewood, you will get the best combustion and it gives you the best heat output.
It is important to note that just adding more wood to a stove will not give more heat, it is burning the firewood with the correct moisture content and with the stove set to the most efficient setting in terms of allowing air into the stove. This makes it the most efficient and gives the most heat output.
What moisture content should wood be?
Firewood moisture content should be between 10% and 20%, any higher and the fire will not be as efficient as it struggles to boil the water content in the logs before it can burn the logs.
It is also worth noting that it is now illegal to sell logs with a moisture content higher than 20% unless you sell more than 2 cubic meters of it, and to which you have to provide instructions to the customer on how to season wood. I also have instructions on how to do this further down.
For anyone with space to buy unseasoned firewood in bulk, this can be much more affordable, but the downside is that it can take between 1 and 2 years to season the firewood so that the water content is less than 20%.
If you buy firewood in small bags, such as from garden centers, petrol stations, or even specialist firewood retailers, you will notice it is now sold as seasoned firewood. This means that it should be ready to use straight away, but I always recommend checking the moisture content yourself before burning any logs.
How to measure the moisture content in firewood
So if you have firewood ready, it is always a good idea to check if the wood has a moisture content between 10% and 20%. This is easily done by investing in a good moisture meter which costs about the price of a couple of bags of logs. It’s a worthy investment and makes checking the moisture content in wood quick and easy.
Most moisture meters have LCD screen/led indicators that will give a reading of the moisture content. The model I use above just has LEDs that light up green when the moisture content is below 20% and then it goes to amber or red the more moisture there is in the wood.
Simply insert the two pins into the firewood (it is worth noting there are a few models that do have pins). It will then give a simple reading of the moisture content, ideally between 10-20%. You should also check several sides of the log to get a fair reading.
If the firewood is not fully seasoned then you need to season the firewood for longer until the moisture content is less than 20%.
Can firewood be too dry?
Firewood can actually be too dry, although it’s not very common to get firewood with a moisture content of less than around 8%. If it is too dry, the wood will burn too quickly and cause the flue to cool at the same time, making the fire less efficient. However, you can still burn them, it’s just not as efficient and they will burn more quickly.
How to tell if the firewood is too dry if you don’t have a moisture meter
If you don’t have a moisture meter there are a few ways to help you decide if your firewood is probably ready to burn.
Firstly any freshly cut logs will not be ready to burn. Hardwood often takes up to 2 years to dry out properly and wood such as pine takes around a year so you will have to season your firewood for at least a year if not longer. Sometimes with pine, it can dry in around 6 months if prepared in spring and stored over summer.
That being said, there are a few ways to help you tell if your firewood is ready to burn as outlined below:
- The wood should be brown, light coloured and NOT HAVE any greenish tints to it.
- It is usually much lighter than freshly cut wood which is another giveaway.
- Seasoned firewood usually has a rough texture rather than smooth.
- The wood is cracking and the bark peels off easily.
- If you bang two pieces of wood together it should be loud and ringing. Wood with a higher moisure content is usually a dull sound due to the water content.
- Should have clear visable rings.
There is also another way called the soap test
Simply apply some soap on the end of the log and blow through the other end of the log like I’m doing above. If bubbles appear in the soap like they are in my photo, this means that the air is passing through the channels where the water is usually stored.
This means it is probably ready to use. You wouldn’t need to do this with every piece, just take a few random pieces of wood that were all cut and stored at the same time and test them. If they all pass the blow test then the woodpile is probably all suitable for burning.
How to season firewood at home
The process of seasoning firewood at home is simple and easy, it just takes a lot longer which is why you need to plan your firewood needs ahead of time. However, if you have access to free logs as I do, it is well worth seasoning your own firewood as it will save you a lot of money, compared to buying kiln-dried logs.
So the first thing you need is a log store, I have actually reviewed some log stores here. You can also make one if you are handy as they are fairly simple structures. A log store will stop rain from falling directly onto the logs, but have an open front and often slatted sides and back to allow air to move freely around the logs. This is essential for seasoning logs as quickly as possible.
You also want to position your log store so it gets plenty of sunlight if possible, and so that the wind can move freely around and through it as this is what dries the logs out naturally.
How to season firewood
You have got a log store, so what next?
Firstly, your logs will dry much more quickly if you cut them up into pieces instead of trying to season full logs. I have been able to season softwood logs in around 6 months by doing this so if you start storing them from spring, you can sometimes have some firewood ready for October as the cold nights draw in. Typically though, it takes around 12 months to 2 years, especially for hardwood logs.
How to prepare logs for seasoning
I like to cut my logs around 16 inches long and around 6 to 8 inches thick.
With your wood cut into the perfect-sized firewood, I then stack them. Now, it’s important to make sure the logs are not stacked on the floor and are raised up a little so air can flow underneath them. Most logs stores are already designed like this, but you can also use a couple of longer logs to lay the log stack on so they don’t directly touch the floor.
How to stack logs in a log store
Make sure you only stack one log thick and stack up to the top of the log store. That’s it, if heavy rain is forecast for long periods of time, you can cover with a tarpaulin to keep the rain off but I find it’s not really needed, and this stops airflow.
If you have issues with blackened glass, check out my guide on how to clean the stove glass with ash here, it is amazingly effective.
To increase the efficiency of your stove I also recommend getting the valiant stove fan which I review here.