Just wanted to share some wood moisture data I collected

[Amin1992]

Hey guys, just wanted to share a bit of data I collected on two sets of firewood I've been monitoring. Sadly I didn't get nearly as many data points as I wanted - lots going on here and it got on the back burner. I know this isn't a lot but found it pretty curious and plan to do more systematic monitoring next year!

First 1/2 cord I have is from a Walnut tree we bucked, split, and stacked almost a year ago - Oct 2020, so about 11 months ago. The Walnut was large (about 50' tall x 26" thick at breast height) and had fallen about a year before we got to it, but fell in a valley so the vast majority of it was raised off the ground.

Date:	Moisture %:
3Oct2020	30%
30Oct2020	26%
22Jan2021	23%
10Aug2021	21%

I started burning this wood at the end of the season. It didn't burn well but good enough at 23%. Sadly we had a lot more campfires here over the summer and ended up burning most of this outside before this season.

Second 1/2 cord is from a dead standing Oak that had died about 8 years ago. Huge tree, at 75+' tall and 36" thick at breast height. We finally cut the tree down Feb 2021 (6 months ago) and bucked and split it from Feb to Mar when time allowed.

Date:	Moisture %:
23Feb2021	33%
26Jul2021	24%
21Aug2021	22%

I was really interested in tracking the Oak as I had been told by many it needed at least 2 or 3 years to fully season, which worried me as I don't have the space to store multiple years' worth of firewood. Granted, this tree was long dead, but it looks like it is seasoned enough for me to use this year, less than a year after being bucked/split/stacked.

All moisture results I took were on fresh splits, and every timepoint I took 2 measurements and recorded the higher of the two. I don't think there was ever more than 1.5% difference between two splits.

Just wanted to share. Thanks!

 

[johneh]

I have often disputed the 3 year drying time for red oak
We cut our firewood in December as soon as the snow comes
and the ground is frozen. It is bucked but not split till march
about half goes into the drive shed and the rest stacked and top covered outside
Come the end of September the inside oak is at 18% moisture content.
The outside is at 19% moisture content It has been this way since I started
to burn wood here 45 years ago. This also goes for Sugar Maple.

 

[Amin1992]

Great to know... that makes me feel better. People call me crazy. My lot is far from ideal too. I get a lot of wind but it's a shady, forested lot so they get minimum sun. Thanks for the input

 

[MongoMongoson]

I haven't taken measurements or tracked them, but from observations... Dead wood seasons faster than green wood. That is, if I cut split and stack some red oak green and then I cut split and stack some more red oak that is two years dead but it is lying on the ground wet, the dead stuff will season faster than the green stuff. Dead standing, even better... even though the wood at the base is generally pretty wet.

 

[Nate R]

Thanks for this!
I have some red oak that was dead standing, cut in December of 2020. Brought some home into my hot attic, and have been weighing marked pieces periodically. I'm not sure what the starting MC was...I believe it was above what my meter reads. But even if it was 100% to begin with after being dead for 18 months, the mini-kiln of my attic is going to take it to under 20% before I burn it this winter. I need to split some pieces and test the MC yet, so I can establish the weight at a known MC, and then back calculate what it started at.

I plan to do this just like you did for future year's wood that seasons outside.... We'll see what kind of #s I get.

 

[stoveliker]

I just measured dead standing red oak css February '19, tarped and dry. 22% for the bigger pieces. Humid summer here...

 

[Rob_Red]

Im struggling to get some Of my oak below 22% it’s been so humid. I’m hoping some cold winter air will get it over the edge.

I’m also trying an experiment with an uncovered stack to see how much of an effect that has

 

[Amin1992]

Thanks all for posting your thoughts. I'm in PA and I feel like getting firewood below 22% is a lost cause. Even if you do get it down to 20%, i think it would naturally rise and fall back and forth from 20 to 25% give or take. I mean even in the dead of winter, the lowest relative humidity here is about 50% so I don't seem wood ever getting down to 20% or below here.

 

[EbS-P]

So here is a link look at table three it tells you the moisture equilibrium content for each month for different cities.

moisture content is different than relative humidity. Things dry fast at RH at 50% and below and more slowly at the RH increases. The theoretical values are generally 14-16% and to my surprise don’t vary that much unless you live in a desert then you can get below 10%.

as wood burners we probably don’t want to wait the length of time that it takes to reach MC equilibrium but we could. Graph of moisture vets date probability isn’t linear as the rate of moisture loss will slow as you get closer to the MC equilibrium point. Just some thoughts.
Table 3 is the relevant bit

(broken link removed)

Evan

 

[stoveliker]

Products - Puuinfo

www.woodproducts.fi

nice graph here.
Ah, I see @EbS-P posted something similar

 

[jaoneill]

I have often disputed the 3 year drying time for red oak
We cut our firewood in December as soon as the snow comes
and the ground is frozen. It is bucked but not split till march
about half goes into the drive shed and the rest stacked and top covered outside
Come the end of September the inside oak is at 18% moisture content.
The outside is at 19% moisture content It has been this way since I started
to burn wood here 45 years ago. This also goes for Sugar Maple.

I am just south of johneh in northern NY and followed roughly the same schedule for over forty years with similar results. Ten years ago we installed a gassification boiler and, in spite of what most would have you believe, it functions best when wood is in the 15% range, the 18%-20% doesn't make it. So I began to experiment with "kiln drying". This will be my fourth year and I think I have the process down. We split right onto pallets in early spring out in an open, windy field and then in June top cover and shrink wrap with vent holes near the top. When we unwrap the 1st pallet in the woodshed in early November, the primarily hickory and sugar maple are at 12%-14%, any cherry is down to 10%-12%. With 1/2 cord per pallet, 20-24 pallets will get us through the winter in good shape. As the pic shows, I managed to get a bit ahead this year with a total of 38 pallets, but only wrapped 24.

 

[moresnow]

I am just south of johneh in northern NY and followed roughly the same schedule for over forty years with similar results. Ten years ago we installed a gassification boiler and, in spite of what most would have you believe, it functions best when wood is in the 15% range, the 18%-20% doesn't make it. So I began to experiment with "kiln drying". This will be my fourth year and I think I have the process down. We split right onto pallets in early spring out in an open, windy field and then in June top cover and shrink wrap with vent holes near the top. When we unwrap the 1st pallet in the woodshed in early November, the primarily hickory and sugar maple are at 12%-14%, any cherry is down to 10%-12%. With 1/2 cord per pallet, 20-24 pallets will get us through the winter in good shape. As the pic shows, I managed to get a bit ahead this year with a total of 38 pallets, but only wrapped 24.
View attachment 281890

Very telling info for those using a gassification boiler. Really makes one wonder what many operators are missing out on for performance. I know it makes a huge difference in a standard freestanding stove.
If you could. A few closeup pics of your assembled pallet/top cover and wrap would likely help guys out.
Do you put anything water proof on the pallets first? I tried a few different versions of your method and had varying success keeping the wrap on. To much wind.

 

[Rob_Red]

I would also be very interested in any info on pallet based kilns.

 

[jaoneill]

I would also be very interested in any info on pallet based kilns.

Do a search on here for "kilns"; I'm sure you'll find a treasure trove of information.....

 

[RockyMtnGriz]

Here's something for you eastern guys, with the hardwood I'm jealous of, to think about:

Yesterday I needed to do a little top off of a wood pile that is going to be burned soon. I selected a couple of long dead lodgepole pines standing in good sun, that I knew would be nice and dry above the bottom 6 feet or so, after our very hot (for here), drought, summer. I noticed it was even lighter than I expected, and split like shattering glass.

I was curious enough to retrieve the moisture meter. The highest reading I could get was 6%, and mostly 3 or 4%! That's why we're having a teentsy little forest fire problem out here in the West!

This wood is going to be gaining moisture in the stack before I burn it, now that the weather is turning.

Now, I think these meters are not so accurate with very dry wood, and I'm not sure if they don't tend to read a little low on wood that's not as dense as average, but even if that tree is standing there at twice what the meter says - that's seriously dry!

I sure do wish it would get on with the snowing though. I've had more than enough smoke this year! Weatherman says maybe a bit next week. I hope so!

 

[Rob_Red]

As a new englander who has red oak to burn for the rest of my days, Im a little jealous of those who have Doug fir!

it’s decent in the BTU department, dries way faster than oak (like a fraction of the time), and splits nicely. I could have HALF the wood inventory I do with a faster drying wood. What else could you want?

 

[johneh]

Nice to have it so dry BUT I think I will stay with my Red Oak, Sugar Maple, and Hickory
It May take longer to dry but heats a lot longer in the furnace with fewer refills

 

[RockyMtnGriz]

We have some doug fir, but it's primarily lodgepole that goes up the chimney here. The fir trees live for hundreds of years longer than lodgepoles, so even though there's a lot of firs, there's not many dead ones, and a lot of competition to take them home. I see poachers taking green ones in the fall just to have some fir, and I'm sure they're burning it wet - what a waste!

The bark beetle came through here about 10 years ago, so dead lodgepoles are everywhere and you can have your pick of easy to harvest ones. I try to keep a little hoard of doug fir on hand for the severely sub-zero times, though. Much better wood, and I can get through a night on something more than a minimum output burn.

There was a time when I lived in a different forest, where it was 75% doug fir, 20% oak and madrone, and 5% cedar in the wood pile. Wood for every situation! I didn't realize how good I had it then. And burning wood wasn't a life or death matter there either.

 

[Woodsplitter67]

As far as oak goes I have it dry and ready to burn in 18 months or less. I think that some areas will have a good area's to dry in some areas will not, I think is has to do with how wet and area is as well as the sun and prevailing winds. It also has to do with how thick its split. The people up in Maine/Vermont will not be able to dry in a year, but PA,NJ, west Virginia,,Ohio should be able to if the woods in a good location. Putting it in a kiln is the fastest way. were you can have wood season in 90 days, 30 days top covered and 60 days wrapped.. My first kiln experiment I left it wrapped to long and my cherry was like 3% my oak was like 8%... Man did that wood burn ..

 

[Caw]

It's all about location and split size for oak. Over this past calendar year I've taken some sipping wet live red oak (40%) down to 20-24% simply top covered on double 1 cord racks (8" air gap between them). They are on the east border of my property and get hit with the prevailing winds and afternoon sun. I also tend to split my oak in the 2-4" range versus the usu 3-5" so it dries faster.

I have 12 cords on 1 acre so I stay 3 years ahead. I always make sure to mix up my woods so I have stuff ready the following year. Maple, cherry, and ash only take one season here. Oak is usually like I said 20-24% after one season in a pinch but it's 10x better after 2 seasons.

 

[MTASH]

Here's something for you eastern guys, with the hardwood I'm jealous of, to think about:

Yesterday I needed to do a little top off of a wood pile that is going to be burned soon. I selected a couple of long dead lodgepole pines standing in good sun, that I knew would be nice and dry above the bottom 6 feet or so, after our very hot (for here), drought, summer. I noticed it was even lighter than I expected, and split like shattering glass.

I was curious enough to retrieve the moisture meter. The highest reading I could get was 6%, and mostly 3 or 4%! That's why we're having a teentsy little forest fire problem out here in the West!

This wood is going to be gaining moisture in the stack before I burn it, now that the weather is turning.

Now, I think these meters are not so accurate with very dry wood, and I'm not sure if they don't tend to read a little low on wood that's not as dense as average, but even if that tree is standing there at twice what the meter says - that's seriously dry!

I live in the same region and could repeat this post word-for-word. Beetle killed Lodgepole reads under 10% on my meter, but it does get erratic at those low readings.

For comparison I cut some Fir in May that blew down over the winter. When cut it was 28-30%. After 6 months, this past weekend I measured a few new splits and got 15-18%.