Moisture Content of Firewood % Chart: Green & Seasoned

Ever tried burning wet firewood, only to be frustrated by excessive smoke and poor heat output? That’s because moisture content plays a crucial role in the efficiency and safety of wood burning. Knowing about moisture content of firewood is essential.

Whether you’re using a wood stove, fireplace, or outdoor fire pit, understanding the moisture percentage in your firewood is essential for achieving the best results.

What is Firewood Moisture Content?

Firewood Moisture Content refers to the percentage of water present within the wood. Freshly cut wood, known as green wood, can contain 30% to 60% moisture depending on the tree species.

As wood dries, or “seasons,” its moisture level decreases, making it more suitable for burning.

Moisture Content (%)

Why Moisture Content Matters in Firewood

Wood with high moisture content burns poorly, producing a lot of smoke and minimal heat. Additionally, burning wet firewood can lead to a buildup of creosote (a sticky substance) in chimneys, increasing the risk of chimney fires.

That’s why knowing the difference between green and seasoned wood matters.

Moisture Content of Firewood Chart

Firewood Type	Green Moisture Content (%)	Seasoned Moisture Content (%)
Ash	35-40	12-20
Beech	70-80	30-45
Black Locust	40-50	20-27
Cedar	45-55	15-20
Cherry	55-70	10-15
Douglas Fir	45-55	13-18
Elm	40-50	15-20
Hickory	40-60	20-25
Maple	40-45	15-17
Oak	75-80	20-26
Pine	45-60	10-15
Poplar	50-60	21-33
Spruce	50-60	10-12.5
Sycamore	35-50	15-20
Walnut	70-80	25-28
Alder	50-60	14-17
Ironwood	12-20	0-5
Sassafras	25-30	10-12
Chestnut	40-57	12-20
Larch	45-55	15-17
Hemlock	31-35	13-15
Cypress	30-45	11-12
Juniper	40-45	15-19
Tamarack	50-60	10-12
Yew	25-35	15-20
Redwood	45-55	18-22
Blue Spruce	35-38	22-25
Balsam Fir	60-66	3-8
Cottonwood	63-70	12-18
Sweetgum	33-42	10-12
Boxelder	45-50	18-20
Black Gum	37-52	9-12
Maple	42-45	10-15
Osage Orange	30-33	14-16
Hackberry	60-64	17-20

How to Measure Firewood Moisture Content

A moisture meter is a reliable tool to quickly measure the water content in firewood. Just insert the prongs into the wood, and it will display the moisture percentage. Recommended Top 5 Firewood Moisture Meters.

Alternatively, you can estimate moisture content by splitting the wood and checking for dampness inside or by weighing a piece to compare its weight over time.

Ideal Moisture Level for Firewood

Over 20%: The wood is too wet, making it inefficient and causing problems like excessive smoke and soot buildup.

Below 20%: This is considered optimal for burning. Firewood at this moisture level lights quickly, burns efficiently, and produces minimal smoke.

How to Properly Season Firewood

Seasoning firewood involves drying it out to reduce the moisture content, making it efficient for burning. Properly seasoned wood burns hotter, produces less smoke, and minimizes creosote buildup in your chimney. Here’s how to do it the right way:

Step 1: Cut the Wood to Proper Length

• Ideal Length: Logs should be 16 to 18 inches long to fit most fireplaces or stoves.
• Splitting Logs: Split the logs to expose more surface area, which allows moisture to escape faster. Thicker logs take much longer to dry.

Step 2: Choose the Right Location

• Airflow: Stack wood in an open area where wind can circulate around the pile. Good airflow speeds up the drying process.
• Sunlight: Place the woodpile in a sunny spot since exposure to sunlight accelerates moisture evaporation.

Step 3: Elevate the Wood

• Use pallets, logs, or a wood rack to lift the woodpile off the ground. This prevents moisture from the soil from seeping into the wood and allows airflow underneath the stack.

Step 4: Stack the Wood Properly

• Loose Stacking: Stack the wood loosely to promote air circulation between the logs. Tight stacking traps moisture.
• Cross Stacking: Alternate the direction of each layer (crisscross stacking) for extra stability and airflow.

Step 5: Cover the Top Only

• Leave the Sides Exposed: Covering the sides can trap moisture, so use a tarp or cover only the top to protect from rain.
• Use a Roofed Shed: If possible, store the wood under a roof with open sides for maximum ventilation.

Step 6: Allow Enough Time to Dry

• Softwood: Typically takes 6 to 12 months to season properly (e.g., pine or fir).
• Hardwood: Can take 12 to 24 months (e.g., oak, hickory).

Step 7: Check Moisture Content Before Use

• Use a Moisture Meter: Insert the prongs into the center of a split log. The ideal moisture content is below 20%.
• Visual Signs: Properly seasoned wood is lighter in weight, has cracks at the ends, and makes a hollow sound when tapped together.

Bonus Tips for Faster Seasoning

• Use Smaller Pieces: Split logs smaller to speed up drying.
• Rotate the Stack: If wood is stored for a long time, rotate the stack occasionally to ensure even drying.
• Avoid Green Wood: Freshly cut wood (green wood) contains high moisture and should never be burned until fully seasoned.

Signs Your Firewood is Ready to Burn

Look for these signs to determine if your firewood is fully seasoned:

• Crackling sound when two logs hit each other.
• Weight loss compared to freshly cut wood.
• Visible cracks and a darker, aged appearance.

Effects of Burning Wet Firewood

Burning firewood that hasn’t been properly dried can cause a host of issues:

• Excessive smoke that pollutes the air.
• Poor heat output requiring more fuel.
• Creosote buildup in the chimney, leading to fire hazards.

Benefits of Using Seasoned Firewood

When you use seasoned firewood, you benefit from:

• Higher energy efficiency, meaning more heat for less wood.
• Cleaner burns with minimal smoke.
• Safer fires with reduced creosote buildup.

How Long Does It Take to Season Firewood?

On average, it takes 6 to 12 months to properly season firewood.

The time required to season firewood depends on Tree species (hardwoods take longer than softwoods), Weather conditions (hot, dry climates speed up drying), Storage method (stacking technique and ventilation).

Tips for Speeding Up the Seasoning Process

• Split wood into smaller pieces for faster drying.
• Store wood in a sunny, well-ventilated area.
• Rotate stacks to ensure even drying throughout the pile.

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