Whether Firewood Can Go Bad (And How You Can Tell)

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

In order for wood to be used effectively as firewood it needs to be dry enough. Lowering the moisture content of wood can be done through seasoning, but seasoning can be a very lengthy process of leaving the wood to dry out for multiple months or even years.

Firewood can also continue to be left inside or outside for a number of years until it’s used on a fire, even if the wood has reached its optimum moisture content.

If wood is left for such a long time does firewood ever go bad?

As long as firewood is left to sit in the right conditions and free from moisture it won’t go bad for many years. Once firewood has been seasoned for the right amount of time it should be stored off the ground, under a form of cover and open to the atmosphere to ensure that it doesn’t rot.

We’ve explained below why your wood may go bad and what you can do to help prevent your firewood from going bad.

Does Firewood Go Bad?

In order for wood to be used effectively as firewood is must be low enough in moisture content for it not burn on a fire with any major issues.

When cut, wood can be much higher in moisture content than what is recommended for firewood. The Environmental Protection Agency recommends that firewood burns its most efficiently when the moisture content is between 15% and 20%.

Newly cut ‘green’ wood will typically have a moisture content that far exceeds the recommended 20%. As an example, we took a branch from a tree on our property during the start of the spring season and measured its moisture content using our moisture meter.

Green Wood Moisture Content

Testing out a ‘green’ piece of wood showed that this particular piece of wood had a moisture content of 45%: much higher than the recommended 20%.

As such, this wood would burn very ineffectively on a fire. It would struggle to catch alight, struggle to burn, may produce more smoke than usual when burning, and would produce much less heat than a dry piece of wood of the same size.

In order for wood to reach acceptable moisture content levels for it to be used as firewood it must be dried out through a process known as seasoning.

Seasoning is the process of letting wood dry out over an extended period of time to allow the weather to naturally lower the moisture content of the wood to acceptable levels for use as firewood.

Seasoning is a long process that can take anywhere from 6 months to two years depending on factors such as the type of wood, the starting moisture content of the wood and how well the wood is exposed to the weather.

To help prevent firewood from going bad and to also help reduce the time it takes for wood to dry out through seasoning, there are some common practices for when stacking wood for seasoning, including:

  • Allowing one side of the stack of logs to be open to the weather elements. The sun and wind will help to dry out the wood much faster than if it was completely covered.
  • Placing the wood on a suitable platform that’s impermeable and dry, such as concrete. This helps for any moisture or rain to runoff into the nearby ground, while also helping to prevent ingress of water into the lower layers of wood that would cause it to go bad and rot over time.
  • Stacking the wood underneath a cover such as an overhang.

To help prevent firewood from going bad during the seasoning process it should not be placed directly underneath something that would cover the entire stack of wood, such as a sheet of tarpaulin.

In doing so the wood can start to go bad and rot due to moisture being trapped underneath the cover and the wood not being exposed properly to the sun and wind.

Firewood won’t go bad if it’s left in the right conditions, which includes ensuring that it’s kept off the ground and covered from the majority of the rain.

Once firewood is seasoned it can either be kept in storage within the same place or moved to another location that also provides the right conditions. Firewood can go bad when placed in storage if not left in similarly dry conditions as when seasoning the wood.

To help prevent firewood from going bad, the Chimney Safety Institute of America (CSIA) recommends that ideal location to store firewood is in a wood shed.

Once our firewood has been properly seasoned we place it into a wood shed that’s located in closer proximity to our wood burning stove. Our wood shed helps to ensure that the firewood remains dry for years

Firewood Shed

To help prevent firewood from going bad over a long period of time the most important thing is to keep the firewood dry, by keeping the firewood off any wet ground and sheltered from the majority of the rainfall.

Another important thing is to allow air to be able to get to the wood. Keeping wood open to the air, especially the wind, will help the wood to remain dry and low in moisture content.

If a piece of tarpaulin or other from of cover is used to protect the wood then one side of the stack of firewood should still be left open and exposed to the weather. This will help to prevent moisture from getting trapped underneath the cover that can cause the firewood to go bad over time.

Wood that isn’t stored correctly can start to rot due to regular and prolonged contact with moisture.

The CSIA states that you can keep firewood stored for up to 3 to 4 years without any issues of the wood going bad if you follow these recommended procedures for storing the wood.

How Can You Tell That Firewood Is Bad?

Firewood should be light in weight and dry to the touch. Other key indicators that firewood is ready to burn include:

  • Course or splitting ends on the logs.
  • The bark is coming away or can be more easily peeled off.
  • The logs will be lighter than wet wood of similar size.
  • When banged together the logs will make more of a hollow sounding noise.
  • The firewood will be a darker brown color with little or no hint of any green.

Here’s what properly seasoned and dry firewood should look like:

In comparison, wood that is starting to go bad will:

  • Have a wet smell and appearance.
  • Will be softer to the touch and may crumble when pressed.

Firewood that is too wet will burn highly ineffectively in a fire because the wood can’t be properly combusted. The higher the moisture content the more energy is required by the fire to burn off the excess moisture before being able to combust the wood.

Wood that is too wet will produce less heat, be harder to catch fire and harder to burn, and can produce more smoke.

You can use a moisture meter to accurately identify whether firewood has been properly seasoned or is going bad. The Environmental Protection Agency recommends that firewood should have a moisture content of below 20% to burn efficiently on a fire.

Moisture Content Firewood

If the moisture content of your wood is starting to increase rather than remain the same level or decreasing then it’s a sign that your wood is starting to go bad.

Whatever type of fireplace you have and however you get your firewood, a moisture meter is an essential tool for any situation.

You can use your moisture meter to better understand whether your firewood is too wet to burn and can help you to identify whether your firewood is starting to go bad.

You can check our recommended moisture meters right here.

Further Reading

Does Firewood Need To Be Covered?

What Does Seasoned Firewood Mean?

Does Firewood Need To Be Seasoned?

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

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