20% moisture content for burning firewood?

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BertP

New Member
Aug 18, 2019
18
New Zealand
20 % moisture content seems to be the rule for burning firewood. We have an enclosed woodburner and when burning wood with a 20% moisture content I can hear sizzling if the glass door is opened. Is That normal? The moisture content was measured in the middle of a freshly split round.
 

brenndatomu

Minister of Fire
Aug 21, 2013
6,389
NE Ohio
No, not normal. Was the wood room temp when you tested it? Is the meter known to be working properly?
 
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CentralVAWoodHeat

Minister of Fire
Nov 7, 2015
667
Virginia
The question of sizzling wood at 20% moisture or under has been brought up in the past. It can be totally normal. Even at 20% moisture, a fifth of that piece of wood is still water.

I get sizzling all the time if I am in the beginning stages of a fire using wood at around 20%. It will boil out through the ends of the splits.
 

Woodsplitter67

Minister of Fire
Jan 19, 2017
1,957
Woolwich nj
The rule of thumb is 20% MC OR BELOW. The advice given to people just starting out with newer EPA stoves. This advice is to help people have a more pleasant experience. If you can get your wood to say 18% or lower that would be even better.. the 20% is just a starting point.
As far as the wood hissing when burning.. your meater may be off.. reading lower that the wood really is..
 

Sawset

Minister of Fire
Feb 14, 2015
1,200
Palmyra, WI
Question:
Will rain soaked pcs alter the equation. I get a pc now and then that sizzles. Usually on the perimeter that was exposed to something - rain, the ground, out on the edge of the stacks when stored somehow. I don't dwell on moisture contents (dry it 3yrs and it is what it is), but if I did, would the split faces read 20, and those perimeters far more?
 

coutufr

Feeling the Heat
Sep 16, 2017
253
Montréal
Below 20% means everything is below 20% or less. You will get a reading here and there at 22 - 23% it´s normal. You should get your wood indoors at least a couple of days prior to burning it. Also the wood should not touch the ground and need to be covered at least 1 year prior to burning it.
 
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Jan Pijpelink

Minister of Fire
Jan 2, 2015
1,945
South Jersey
Below 20% means everything is below 20% or less. You will get a reading here and there at 22 - 23% it´s normal. You should get your wood indoors at least a couple of days prior to burning it. Also the wood should touch the ground and need to be covered at least 1 year prior to burning it.
I guess you mean should not touch the ground.
 
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Sawset

Minister of Fire
Feb 14, 2015
1,200
Palmyra, WI
I guess you mean should not touch the ground.
Woodchucks. Hard to control. Making the best of it.
Below 20% means everything is below 20%
But that's not what we're always told. Split, measure a face -
That's why I've never relied on a moisture meter. If I had xx cords, I'm not buying fake logs to fill in - it's going in - pull the dry and go. I can open up the air some to compensate and keep the stack temps up if need be. Early on I did just that, but not now with a few years ahead.
 

coutufr

Feeling the Heat
Sep 16, 2017
253
Montréal
You are right. It should NOT touch the ground (thanks for flagging it: I just edited my post). I keep a good 4 to 6 inches of space between the wood and the ground.

Having a few years ahead and optimal drying conditions at least during the last summer of drying helps to make the wood uniformly dry. Splitting smaller is also important if you don’t have the luxury of being 3 + years ahead. I like to use the moisture meter when I scrounge wood that is partially dry (many years old unsplit and or uncovered wood). It gives me an idea of how soon I can integrate it into the rotation.
 
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kennyp2339

Minister of Fire
Feb 16, 2014
5,924
07462
I've had a few head scratchers were I've measured 16% on a split and heard a sizzle.. didn't really worry to much about it.