Firewood Shed

Does Firewood Need To Be Seasoned?

In Firewood, Indoor Fireplaces by James O'KellyLeave a Comment

Firewood is typically sold as either seasoned or kiln dried to inform the buyer that the wood is ready to be used inside a fireplace or stove.

Freshly cut wood can have a much higher moisture content than seasoned wood, but bringing moisture content levels in wood down through seasoning is a lengthy process.

So does firewood need to be seasoned?

Wood needs to be sufficiently dried out before it can be used as firewood, otherwise it will burn ineffectively in a fire. The main process for drying out wood can be through seasoning, which helps to naturally lower the moisture content of the wood over a prolonged period of time.

The moisture content of firewood can dictate how well it burns in a fire, as well as how much smoke it produces and how much heat it can generate.

We’ve therefore discussed in further detail below why firewood needs to be seasoned and what happens when you burn wood that is too wet.

Does Firewood Need To Be Seasoned?

Seasoning is the process of naturally drying out wood so that it can be used effectively as firewood.

Freshly cut wood is left outside to dry for an extended period of time until moisture levels within the wood reach acceptable levels. If wood is used in a fireplace or stove before the acceptable moisture level range is reached then it can experience a number of problems as a fire tries to burn through it.

The main problems experienced when burning wood that is too wet include:

  • Being harder to catch fire.
  • The fire will struggle to burn the wood even if it eventually catches fire.
  • More smoke can be produced as a result of incomplete combustion of the wood.
  • Burning wet wood can increase the build up of soot (tar/creosote) within your chimney, flue, or on the glass of your fireplace insert or stove.
  • Less overall heat will be produced because the wood can’t be properly combusted.

It’s therefore important to be able to bring down the moisture content of wood before it’s used on a fire. As the moisture content of wood increases above recommended levels then these issues can become more noticeable.

Trees are naturally high in water content, and once the wood is cut it will therefore be high in moisture content.

The moisture content of wood can be measured as a percentage. The starting percentage of the wood can be dictated by:

  • The type and species of tree.
  • The time of year the wood was cut.
  • The health of the tree.
  • Other factors.

If a piece of wood has a higher starting moisture content percentage then it can take longer for the wood to season (dry out) as a result.

It’s therefore preferable to cut wood during the winter months when the moisture content levels are at their lowest.

Freshly cut ‘green’ wood will a greenish tint to it, will have bark that is soft and will peel away in layers, and will have an overall wet feel to it. Wood with these qualities is a sign that the wood is too wet to be used as firewood.

You can check the exact moisture content level of wood by using a moisture meter.

Moisture Meter
Our moisture meter that we use to identify how well seasoned our firewood is

Simply turning on the moisture meter and pressing it firmly against any piece of wood will give you a moisture content reading.

To show how wet ‘green’ wood can be we cut a branch from a tree located on our property (during the start of the Spring season) and used our moisture meter to give a moisture level reading.

Green Wood Moisture Content
The moisture level of wet wood is far too high to be used efficiently as firewood

The moisture meter showed that this piece of wood had a moisture reading of 35%. The display on our moisture meter also turned red because the wood is above the recommended moisture content range for firewood.

The Environmental Protection Agency (EPA) recommends that the moisture level for firewood should be between 15% and 20% for it to burn its most efficiently on a fire.

Our moisture meter turns amber when a piece of wood has a moisture reading within this range.

Anything below 15% and our moisture meter reads the moisture content with a green background.

Moisture Firewood
Example of the moisture content of seasoned firewood

A moisture meter is an essential tool for any fireplace and can help you to understand how well your firewood will burn in your fireplace or stove. We’ve helped prevent so many of our fires from struggling thanks to using a moisture meter to read the moisture content of our wood before it’s burnt.

From our experience buying ‘seasoned’ wood doesn’t always mean that the moisture content is low enough for it to burn efficiently!

You can find our recommended moisture meter here, or if you’re in the UK you can check out the exact moisture meter we use here (which has the awesome benefit if turning red, amber or green depending on the moisture level reading).

The freshly cut branch that we used to explain the moisture content of green wood would have burnt highly inefficiently if used in any of our fires.

It would have struggled to catch alight, and if it eventually did catch fire then the fire would continue to struggle to burn it. This is because more energy is required by the fire to burn off the excess moisture content before the wood can be properly combusted.

As such, the higher the moisture content of the wood, the more it will struggle to burn in a fire.

Wet wood can produce more smoke than seasoned wood while a fire is trying to burn off the excess moisture, leading to more tar being produced that can line the insides of your chimney or flue, and stain your fireplace or stove glass. You’ll find that you’ll need to have your chimney swept more often as a result.

Burning wet wood can cause the glass on your fireplace or stoves to stain at a quicker rate

Burning wet wood will lead to struggling fires that can have a much lower heat output compare to properly seasoned firewood that is low enough in moisture content.

So does firewood need to be seasoned? Yes, wood needs to be dried out, whether it’s through seasoning or kiln drying, in order for it to burn effectively on a fire and for you to get the most amount of heat from your fireplace or stove with as little issues as possible.

We season our own firewood before it’s used in our wood burning stove.

Apart from having the right setup to help wood to season as quickly as possible, there’s no cost involved when seasoning your wood. The only downside to the seasoning process for firewood is that it can take months or even years for the wood to reach recommended moisture content levels.

Hardwoods are typically denser than softwood logs and so they can take longer to dry out. Depending on factors such as the moisture content of the wood when it was cut, softwoods can take from 6 months to a year to season while hardwoods can take anywhere up to 2 years to dry out.

Here’s how we season our firewood:

To help the wood dry out as quickly as possible, we’ve set up the way the logs are stored to ensure that:

  • The wood is stacked so that one side is open to the weather. The wind and sun helps to season the wood more quickly.
  • The wood is under a cover such as an overhang (but not directly covered over such as with a piece of tarpaulin).
  • The logs are stored on an impermeable dry surface such as concrete.

Another way to dry out wood is through kiln drying, which vastly speeds up the drying process.

Wood is placed into an oven-like kiln and can dry out in a matter of days. As this is a more involved method of drying wood it can be reflected in the price of kiln dried wood compared to seasoned wood.

However, we’ve found our kiln dried wood to be even lower in moisture content than our seasoned wood, so low in fact that our moisture meter can’t even give a reading (meaning that it’s less than 6.8% moisture content as this is the lowest reading our moisture meter can give).

Firewood Moisture Content
Kiln dried firewood can have very low moisture content levels

Compared to wet wood, seasoned or kiln dried wood will burn much more effectively in a fire and so it’s important that wood is dried out before being used as firewood.

So does firewood need to be seasoned?

Yes, all wood should be seasoned before it’s used as firewood. Burning wood that is too wet will lead to numerous issues that will cause frustration when having fires in your home.

A moisture meter will help you to identify which of your logs are will burn better in your fires.

Further Reading

What Moisture Content Firewood Should Be (And How To Check)

Should Firewood Be Covered?

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