Moisture content of dried wood.

[Chas0218]

New to the forum, and somewhat New to wood stoves. I grew up around wood stoves and cutting firewood. My question has to do with moisture content. I checked the moisture content of wood I cut yesterday and it read 28% this was silver or sugar maple. I didn't really pay attention to which it was. Is it normal for"green" wood to have that low of moisture one day later?

I also cut ash that was lying in tact for the last year and is at 35%.

Do those percentages sounds right?

On a side note...I have locust at 20% some lower is that low enough for efficient burn?

 

[begreen]

Welcome. Are these end grain readings or on the freshly exposed face of re-split wood?

 

[jatoxico]

Hey Chas, welcome. Moisture content should be measured by making a fresh split and then quickly taking your reading. Readings from the ends or from splits that have been sitting out won't give the real picture.

Green wood (most) will read around 40%. The meters lose accuracy when reading over a certain percentage. 28% sounds a little low for green wood if you make a proper test.

 

[TheRambler]

Only way it would be 28% was if it was a dead limb/standing dead tree.

And a +1 for the above mentioned way to check with a mm

 

[Chas0218]

The locust was a split piece and reading was taken on the side (length wise down split).

The Maple was tested on the end grain (cut to 16" lengths not split).

The Ash was tested on the end grain (cut to 6' lengths not split).

On a side note I took a moisture reading of some wood (I think was either Box Elder or Hickory) that had been lying for a year and was 24%.


All the readings were taken with a digital moisture meter non-probe style. It said my hand's moisture content was around 60% haha

 

[Chas0218]

I forgot to mention that the wood was trailered 50 miles in *75 temperatures. Not sure if that matters being as it was stacked on their sides facing split ends into the wind.

 

[TheRambler]

Measuring the end grain will never give you an accurate reading. You have to split it and check a freshly split face.

For clarity, your mm reading is technically accurate measuring anywhere. But to get the reading most meaningful would be to check the middle of a given piece, which is accomplished by testing a freshly split face

 

[NYSB]

Chas -

I'm not the greatest expert as I have been burning wood for only one season, but I can share my own experience. How the wood is cut, split, and stacked makes a difference. I have about 2 cords of oak and Norway maple mix that I cut and split myself last spring, which I intend to burn this season. Most of it was cut dead standing and was reading 25-30% at the time it was split. Some was closer to 35-38%. This weekend I spent some time evaluating the moisture content and I compared an end-grain reading vs. freshly-split face readings in about 20 pieces. I had some very large pieces on the bottom of the stack that were more the 20%, but most of the wood I checked was 15-20%. Comparing the two reading methods I found the end-grain reading was usually no more than 1-2% lower than the split-face reading for wood that was under 20% and 6" and under splits (thickness). On some of the very large pieces, say 8-10" and larger, there was more variation in the moisture readings although even then it was pretty close.

Most of the modern stoves specify wood that is 20% or under. Clearly burning green wood is not good, say 30-40%, but I don't know that burning wood a little over 20% is all that bad. If I have wood that is more that 20% (within reason) that I want to burn I'll mix it with some drier stuff in the stove. Too much moisture robs the stove of heat output because the water content has to be boiled away as steam, which takes a lot of heat energy, so overall stove performance decreases. That steam is then carried away into the flue where it can condense and increase creosote formation. Lastly, with higher moisture wood it takes longer for the stove to get back up to operating temperature at the beginning of each fuel cycle, so there is more time when the stove is not working at peak efficiency and less time with no visible smoke.

One thing I've found is that if I have wood with MM > 20% I'll split it into smaller pieces if it's very large and store it inside the house, about 6 feet from the stove where the air is very warm and dry. After a day or two this will reduce the moisture in the wood a bit.

Good luck - stove season is rapidly approaching!

 

[TheRambler]

I am sure every situation is a bit different vased on variables etc. but i see a difference of 10% or greater when comparing end grain measurement vs fresh split face. Especially so if it was live wood when it was cut. Dead standing would stand to reason there would be a smaller spread in readings.

 

[Chas0218]

Ok so I will split some pieces tonight and get a more accurate reading. I wasn't entirely sure where to take the reading. I will say that the pieces I put in the back of the truck split are wet. Last night I closed the tonneau cover and man did those logs let off a lot of moisture. The cover looked like it was raining inside my truck pretty crazy.

Thank you everyone for the help. I am planning on using the wood stove to heat our 960 square foot cottage during the ice fishing season. So I won't be using it other than a few weekends a year but I want to have an easy time starting and maintaining a fire. That being said dry wood is important in this situation as I have no other means of heat.

 

[Chas0218]

So I split some more of the maple and it was reading 34% on the split face. When I was splitting the wood it was making that nice loud crack with next to no thud. O well maybe it won't need to season as long.


I did read on my meter that for hardwood it will only read up to 35%.

 

[NewHarmanOwner]

34-35%, that's pretty high. It'll take at least another 6-7 months to get it down to 20s. And considering winter is coming up....

I don't know about your dry wood.

 

[Chas0218]

My dry wood is good reading 19% and 20% also considering it is black locust that is reading that low. I have been doing a lot of searching and it seems black locust is hard to get lower than 20%. I won't be using this stove non stop during the winter but probably for 2 days straight just while I am ice fishing.

I have some other wood that is reading 26%-30% do you think that will be ready for winter? Just curious, I live in northeast NY.

 

[kennyp2339]

When measuring you want to test the meter on a freshly split piece of wood, you also want to find the grain (length) and put the probes firmly into it running parallel.

 

[blades]

Black Locust isn't a real high moisture wood- but it requires a very hot bed of coals to get it to burn well. If I may ask what kind of stove? The answers supplied so far are based on the current crop of EPA regulation conforming units. The old steel or cast box stoves- fancy versions of a 55gal drum with a door and a flue attached ( read in-expensive) are not as finicky.

 

[Applesister]

Locust smells like burning socks, you need some apple wood for your fishing cottage. I'll assume the stove is an older model, and the wood will smoke a little.
You're working with some green numbers there, maybe some sugar maple to really tweak your appetites after a long day on the ice.
Maybe a wood cook stove with some beer batter Sunfish.
Yum.
Best smelling semi seasoned firewood:
Yellow birch
Black cherry
Crab apple
Sugar maple
Apple
Hickory
Seriously, major difference between 20% and 17%

 

[illenema]

10-15% = ready to burn efficiently. 20% very iffy

 

[Chas0218]

Don't stone me but I got a decent deal on a vogelzang defender with all the needed piping. Paid $450 and the stove was New last winter.

I just split the ash tonight and that was reading between 26% and 23% anyone think that will be seasoned enough with 2 months before freezing? Should be in the mid 80s for the next couple weeks.

 

[zig]

The ash will be fine. Actually, I split and stacked 4+ cords if green silver maple last oct. in an open spot with sun and wind. Stacks collapsed because of drying and i re- stacked this spring. 24% average over the winter, uncovered in a -20 Mi. winter. Maybe freeze dried?

 

[Applesister]

The weather could be in your favor, and there are things you can do to speed things up like splitting small etc.
At 23% you need to have alot of dry kindling, twigs, lots of pine cones, newspaper.
I dont know if you want the added expense of buying pressed wood blocks but you can get hot coals going then drop the less dry wood on top.
My sister has a new stove that loads with the split's endgrain facing the glass, we took pictures of the water bubbling out the ends of the splits. Never seen that before.

 

[maple1]

Your meter doesn't have probes?

I would verify its accuracy with a multimeter. There is a chart on this place somewhere with an ohms vs. m.c. relationship, I think.

 

[Chas0218]

No probes you just press it into the wood. It's supposed to read interior moisture these style are popular with the boating industry they are supposed to read under the fiberglass.

 

[maple1]

I would still verify it with a multimeter.

 

[Chas0218]

In case anyone is looking for the thread that has the chart. I didn't know that you could do that. I mean it makes sense just never though of doing it that way. Only down fall to the chart is that it doesn't have cherry on it.

https://www.hearth.com/talk/threads/using-a-multimeter-to-measure-wood-moisture-level.40033/

FWIW I had some mystery wood that I thought was maple but turned out to be cherry (very pink sap wood and split stringy). Kind of wish I didn't hunk it up for firewood and instead made boards out of it.

I will check wood tonight using multimeter and compare readings from my MM. If they are close I'll know I can trust my meter otherwise I'm just going to sell it. haha

 

[Typ0]

Don't stone me but I got a decent deal on a vogelzang defender with all the needed piping. Paid $450 and the stove was New last winter.

I just split the ash tonight and that was reading between 26% and 23% anyone think that will be seasoned enough with 2 months before freezing? Should be in the mid 80s for the next couple weeks.

I just split more than a cord of ash I plan on burning this year too. I am not discounting the freezing temperatures as drying time though....I mean there is two really cool things in the winter around here a ton of sun and wind. The wind can break down ice and freezing and unfreezing squeezes water out of the center of the wood. I am counting on my wood being ready to burn in February....I am splitting the stuff I am going to be burning then smaller though.