Do moisture meters work for firewood?

When it comes to preparing firewood, having the right moisture content is crucial for clean and efficient burning. But how can you be sure your firewood is adequately dried? This is where a moisture meter can come in handy.

What is a moisture meter?

A moisture meter is a tool used to measure the moisture content in various materials. For firewood, a pin-style moisture meter with insulated pins is used. The pins are inserted into the firewood, allowing the meter to detect the electrical resistance. Since moisture conducts electricity, while wood does not, the more moisture present, the lower the resistance reading. This reading is then converted into a moisture content percentage.

Why measure firewood moisture content?

Measuring and monitoring the moisture content of firewood is important for several reasons:

• Burn efficiency – Wet firewood burns inefficiently as energy is wasted heating and evaporating excess moisture rather than heating your home.
• Creosote buildup – Wet firewood can lead to more creosote buildup in chimneys and stovepipes, increasing the risk of a chimney fire.
• Difficulty starting fires – Excess moisture makes it harder to start and maintain a good fire.
• Incomplete combustion – Wet firewood prevents full combustion, resulting in more smoke and air pollution.
• Heating power – Dry firewood provides significantly more heat energy when burned versus wet wood.

Testing firewood moisture levels with a meter ensures you know exactly how seasoned your wood is for safety and optimum fire performance.

What is considered adequately dry firewood?

Ideally, firewood should have a moisture content between 15% to 20% before burning. Here are some general guidelines for good seasoned firewood:

Moisture Content	Assessment
Under 15%	Very dry, may burn too quickly
15% – 20%	Ideal moisture level for burning
20% – 25%	Suitable for burning, may pop and hiss
25% – 30%	Borderline wet, may be difficult to burn
Over 30%	Too wet, will not burn efficiently

Wood moisture content over 30% is considered too wet for proper seasoning. The higher the moisture content, the more problems you’ll encounter trying to start and maintain fires.

When to test firewood moisture

Testing your firewood’s moisture at different points through the seasoning process ensures it’s drying properly. Here are some good times to use your moisture meter on firewood:

• When the wood is first split – Gives you a baseline starting moisture level.
• Periodically through drying – Monitors downward moisture trend.
• Before and after summer drying – Tests impact of peak summer heat.
• Near end of seasoning period – Confirms target moisture reached.
• When loading wood to bring indoors – Checks final readiness for burning.

Testing more frequently provides better data to track the wood’s drying progress and identify any problem spots that may need more air circulation or time to dry.

How to use a moisture meter on firewood

Using a moisture meter designed for firewood is simple. Here are the basic steps:

1. Split wood to expose fresh inner surfaces.
2. Push pins into wood at least 1 inch from edge and 3 inches apart.
3. Hold pins in place per device instructions.
4. Read moisture percentage on LED display.
5. Take readings in several locations to obtain average.
6. Re-split large logs and retest interior.

Always refer to your moisture meter’s specific instructions for accurate use. Proper technique is important for precise moisture readings.

Tips for accurate firewood moisture readings

• Test fresh-split surfaces – Provides most accurate reading.
• Re-split large logs – Tests inner wood vs just the outer surface.
• Allow time to stabilize – Up to 5 minutes for reading to equilibrate.
• Calculate average – Use multiple readings across and inside wood for best average.
• Avoid knots and defects – Gives higher false readings.
• Check meter calibration – Ensure accuracy with test blocks.

What are the limitations of firewood moisture meters?

While moisture meters for firewood are convenient and useful, they do have some limitations to be aware of:

• Surface reading only – The pins can only measure moisture at the insertion point, not the interior of a log.
• Wood density affects accuracy – Softwoods like pine can give lower readings than dense hardwoods at the same moisture level.
• Ambient humidity impacts readings – Very dry or humid air conditions can skew results up or down.
• Doesn’t account for log shape – Round logs with bark take longer to dry than split wood but give similar readings.

While meters provide a reasonably accurate moisture estimate, fully dried and seasoned firewood is ultimately confirmed by properly burning the wood in a stove or fireplace.

Signs your firewood may still be too wet

In addition to using a moisture meter, there are some visible and audible signs that can indicate if your firewood may still be too wet to burn properly:

• Dark wood color – Unseasoned wood will be darker than properly dried firewood.
• Mushrooms or mold – Excess moisture encourages fungal growth on the wood.
• Peeling bark – Bark detaching from the logs signals unfinished drying.
• Cracks between rings – Checking or cracks along the wood grain are signs of uneven drying.
• Dull or hollow sound – Wet wood thuds rather than producing a bright ring when struck together.
• Heavy weight – Wet wood feels significantly heavier than seasoned dry firewood.

Paying attention to these indicators along with moisture readings can help confirm your firewood is adequately dried and seasoned for efficient fires.

Using a moisture meter ensures quality firewood

Relying solely on the length of seasoning time or guesswork is risky when preparing firewood. A quality moisture meter designed for firewood takes the uncertainty out of the equation. Periodically testing your wood’s moisture content as it dries provides confidence it will burn properly when you need it.

While they have some limitations, moisture meters are an indispensable tool for monitoring the seasoning process. Combined with knowledge of proper drying times and conditions for your climate, you can use a meter to validate that your firewood is sufficiently dried and ready to heat your home efficiently and safely.