Log moisture content explained: dry enough?
Moisture content is the share of a log's weight that's water. Wood sold under the Ready to Burn label is at or below 20%, and that's a sensible target for your own logs too. The only way to know is to measure: split a log, let it reach room temperature, and press a moisture meter into the fresh face.
Why moisture matters
Water in a log does three things, all bad:
- Less heat. Some of the fire's energy goes on boiling the water off instead of warming the room.
- A cooler, smokier fire. Wet wood smoulders, which leaves tar in the flue and soot on the glass.
- More logs. You burn more to get the same warmth.
Dry logs catch quickly, burn brightly and leave the glass clearer.
How to measure properly
A pin-type moisture meter reads in seconds, but only if you use it the right way:
- Take a log from the middle of the stack, not the top or the outside.
- Bring it indoors for a day so it's at room temperature. Many meters read wrongly on cold wood.
- Split it, and measure on the freshly split face. The outside and the cut ends dry first and read drier than the middle.
- Press the pins in along the grain and take three readings across the face.
- Average them. If one reading is well above the rest, test another log from the same batch.
Set the meter to its wood setting, and check its manual for how it reports moisture.
What the reading means
- At or below 20%: ready to burn.
- Above 20%: keep seasoning, then measure again in a few weeks.
Our log moisture checker averages your readings and tells you which side of 20% they fall.
Getting logs drier
Split logs dry far faster than whole rounds. Stack them off the ground, cover the top, and leave the sides open so the wind can get through. See how to season firewood and how to store logs.
FAQs
What moisture content should logs be?
At or below 20%, measured on a freshly split face. That's the Ready to Burn threshold for wood sold in small volumes.
How do I check if my logs are dry?
Split one, let it reach room temperature, and use a pin moisture meter on the fresh face. Take three readings and average them.
Why does my meter give different readings on the same log?
The outside and the ends dry first, so they read drier than the middle. Always measure on a freshly split face, along the grain.
Can I burn logs above 20%?
They'll burn, but cooler and smokier, with less heat per kilo and more tar in the flue. Keep seasoning them and measure again.