How dry is dry enough?

  • Active since 1995, Hearth.com is THE place on the internet for free information and advice about wood stoves, pellet stoves and other energy saving equipment.

    We strive to provide opinions, articles, discussions and history related to Hearth Products and in a more general sense, energy issues.

    We promote the EFFICIENT, RESPONSIBLE, CLEAN and SAFE use of all fuels, whether renewable or fossil.

Sodbuster

Minister of Fire
Sep 22, 2012
1,526
Michigan
OK, so I think I have enough wood to make it through the winter, but my stacks are not as large as I would want. Due to an injury and illness, I am just getting to cutting to bolster my stacks. I'm fortunate that my neighbor lets me cut dead wood on his 10 acres. I harvested some dead Ash and dragged the 20' logs to my processing area. Moisture readings are between 16-17% and I'll get them CSS this weekend. Will this wood be good for this winter, or should I let it season over the winter, it will make a difference in how I stack it. Thank-you.
 
  • Like
Reactions: patrickk222
You won't know the true moisture content u told you buck and split the logs. The outer portions will not give you an accurate number. Once you proceed it split a fresh round and take a reading. Normal you want it at room temp for full accuracy but it's warm enough still this will be fine.

Ideal MC is 15-20% but with ash you can often get away with 22% or so and be OK. If you have anything drier you can mix it in to compensate.

If you get stuck head down to the local Tractor Supply type store and grab some compressed sawdust bricks to mix in with the mediocre dry-ness wood. That will really help.

Good luck!
 
You won't know the true moisture content u told you buck and split the logs. The outer portions will not give you an accurate number. Once you proceed it split a fresh round and take a reading. Normal you want it at room temp for full accuracy but it's warm enough still this will be fine.

Ideal MC is 15-20% but with ash you can often get away with 22% or so and be OK. If you have anything drier you can mix it in to compensate.

If you get stuck head down to the local Tractor Supply type store and grab some compressed sawdust bricks to mix in with the mediocre dry-ness wood. That will really help.

Good luck!

Thanks Caw, the reading I took on the Ash was from a fresh cut from the middle of the tree, (14"____________x____________16"), the reading was from the center of that cut. From what you are telling me, I should be good for this year, especially if it not used for a month or two.
 
Is that on the end grain or a fresh split? It needs to be on a fresh split with the prongs on the same line, not across the grain, or you'll get false low readings. You'll know immediately upon burning it if it's dry or not

Here's what it should look like when you're measuring. This is red oak that was CSS 2 years ago:

PXL_20220917_191336337.jpg


PXL_20220917_191336337.jpg
 
  • Like
Reactions: stoveliker
Maybe you got lucky and the tree dried out while standing there - Ash in a Flash. The wood down by the trunk might have a higher moisture content, though.
 
  • Like
Reactions: JayD
Ash definitely is fast drying and can be about ready to burn on the top of the tree when you take it. Just make sure to measure it properly and take readings at different section as just mentioned. The top will be way more dry than the bottom.

If you throw a 28% MC log on some 300 degree coals you will know within 20 seconds and be sad. It will just smoke and smolder and do nothing whereas an 18% piece will catch and go. It's really quite a stark contrast.
 
  • Like
Reactions: ozarkoak
It was on an end cut; I just got in from bucking up the largest part of the Ash, a nail from an old tree stand shortened my cutting for the day🤬. I was able to split a round from the middle of the tree, I got 19% from the middle of the split to 15% halfway out, and 13% toward the outside. The "butt" end of the tree was visibly wet and came out from 25-31%.
 
Yep. I've had standing dead ash with limb branches ready to burn under 20% and the trunk still over 40%... Standing dead for years...

The trunk of a dead tree acts as a wick. I had some dead standing black ash in the swamp in the Northwoods that still wouldn't even register on my moisture meter after css for a year.
 
Ash has an open pore wood structure and dries quite quickly, certainly usable in one year from splitting and if dead standing, possibly ready to go right away.
 
Good.. I have a bunch of ash from falling dead trees. Just found two more that I am cutting up now. Hoping some will be ready Feb/Mar time frame
 
Is that on the end grain or a fresh split? It needs to be on a fresh split with the prongs on the same line, not across the grain, or you'll get false low readings. You'll know immediately upon burning it if it's dry or not

Here's what it should look like when you're measuring. This is red oak that was CSS 2 years ago:

View attachment 300111

View attachment 300110
ALONG the grain...ah I never knew that. This changes everything. Now what am I supposed to do with this tattoo of a MM testing wood ACROSS the grain!?
 
  • Like
Reactions: ozarkoak
It was on an end cut; I just got in from bucking up the largest part of the Ash, a nail from an old tree stand shortened my cutting for the day🤬. I was able to split a round from the middle of the tree, I got 19% from the middle of the split to 15% halfway out, and 13% toward the outside. The "butt" end of the tree was visibly wet and came out from 25-31%.

If the wood.is 25 to 30.. Id split a little smaller then normal and stack and top cover.. ash like poplar will season over the winter.. I split popular in January one year and burned in in April and may as my should season wood.. I wouldn't wait any longer.. your well north..
 
Is that on the end grain or a fresh split? It needs to be on a fresh split with the prongs on the same line, not across the grain, or you'll get false low readings. You'll know immediately upon burning it if it's dry or not

Here's what it should look like when you're measuring. This is red oak that was CSS 2 years ago:

View attachment 300111

View attachment 300110

FWIW, those General meters (at least mine) reads consistently low by about 4%. The orange one on the right matches what someone else's meter shows and theirs matches what an EPA testing agency uses. I have stopped using the General and only use the four pronged orange one.


1666203575796.png
 
  • Like
Reactions: sloeffle
The beauty of the 4-point measurement : contact resistance falls out of the equation.
 
  • Like
Reactions: sloeffle
FWIW, those General meters (at least mine) reads consistently low by about 4%. The orange one on the right matches what someone else's meter shows and theirs matches what an EPA testing agency uses. I have stopped using the General and only use the four pronged orange one.


View attachment 300853
That sucks. I just bought one of those. This is the problem with the internet at large. The general tools had by faaaaaaaar the most reviews and mostly all positive. So I'm like that one seems good.
 
  • Like
Reactions: Northern NH Mike
That sucks. I just bought one of those. This is the problem with the internet at large. The general tools had by faaaaaaaar the most reviews and mostly all positive. So I'm like that one seems good.

It could be just mine, I don't know. I'm planning on sending the General one to someone and have them compare it to theirs.

One would think the red oak I posted in the photo (C/S/S in spring '15) would be closer to 14% than 18%....but that's not what the other guys meter said. As his matched what my orange one said.
 
Last edited:
  • Like
Reactions: sloeffle
It's the contact resistance taken out of the equation. Google 4-point measurement.

The MM measures the total of three resistances in series: contact pin-to-wood, wood, and contact wood-to-pin.

The four pin one only measures wood.

Therefore, the MM measures a higher resistance and thus reads a (incorrectly) lower moisture content per the calibration table.
 
  • Like
Reactions: JRHAWK9
FWIW, those General meters (at least mine) reads consistently low by about 4%. The orange one on the right matches what someone else's meter shows and theirs matches what an EPA testing agency uses. I have stopped using the General and only use the four pronged orange one.


View attachment 300853
well that's just GREAT! Here I thought I had two cords ready to burn.
Oh, and I have been determining the gaps I leave now that the air is much drier and based on MC of my wood plank paneling before nailing it up.
My only solace is that I used the same meter to measure my highest range through summer high humidity, and my paneling got to about 13%. At 8%, I know I basically have to leave a quarter sized gap between each board so that they will expand and not try to pull away from the wall. Or at least I hoped.
 
  • Like
Reactions: ozarkoak
Interesting.. Does anyone know if someone has compared moisture meters. I got a Stihl meter.
 
I wonder who makes it for Stihl?? If that's the one you want, I would try to find out and buy it direct from the manufacture to avoid paying the "orange" tax.
 
It's the contact resistance taken out of the equation. Google 4-point measurement.

The MM measures the total of three resistances in series: contact pin-to-wood, wood, and contact wood-to-pin.

The four pin one only measures wood.

Therefore, the MM measures a higher resistance and thus reads a (incorrectly) lower moisture content per the calibration table.

So, what you are saying is the 2 post meters are nothing but a multimeter calibrated such to give a moisture percentage readout.
 
Yes. They simply measure resistance.

In fact you can do it yourself by putting in some nails at a certain separation, hooking up a multimeter and measuring the resistance. The calibration tables are available online someplace.
 
I don’t have three hands to take a picture and hold both meters. I tested a piece of ash that’s been sitting in my basement and hit the hold button once the numbers were no longer moving. Checked it roughly in the same spot with both meters.

The meter of the left came with my Heatmaster OWB.

8944D7D2-7371-4245-88A5-7727EF9E7EAC.jpeg
 
I don’t have three hands to take a picture and hold both meters. I tested a piece of ash that’s been sitting in my basement and hit the hold button once the numbers were no longer moving. Checked it roughly in the same spot with both meters.

View attachment 301021


;lol Well, this sure doesn't prove anything! Completely opposite of what I showed.

Just stick the meters in far enough so they stay! :p

They sure did give you a pricey meter with your HM!!
 
Last edited: