Green wood moisture content

I took the U Nebraska firewood chart and put it into a spreadsheet. Out of curiosity, I wanted to know how much water is in different species of trees when green.

Here's how I calculated it. First I figured the weight per cord of totally dry (0% moisture) wood. I assumed that the "dry" weight given was 20% moisture for this purpose. That is the 3rd column over. From that I divided dry weight by green weight to get the percentage of water in green wood. This is the far right column.

EDIT: Thanks to Shari (Wife&Hubby) for cleaning up my txt file and making a nice jpeg to look at:



Kind of suprising that some softwoods and some of the hardest were at the top of the list. (I sorted for dryest to wettest.)

Part of the reason for this is we're getting to the time of year where 4,000 people will ask "what's the best wood to burn green". I'd think that the driest woods on this list would be best for burning green, as there will be less heat lost boiling water, but I'm probably not seeing some other points.

Class, discussion is now open.

BTW, I just used notepad to open the text file when I previewed the post.

Many Tanks fer da early postin' dere Steve!

I see what ya did there. I read the chart the other way and assumed retained weight at zero at first.

Wierd. I always thought ash was better than Black Cherry and Red oak when Green.


Stay safe!
Dingeryote

There is a similar chart about 3/4's of the way down the page under "Regarding Seasoning of Wood".
http://mb-soft.com/juca/print/firewood.html

Steve,

Thanks for the added comparisions! I 'collect' charts.... beginners have to do that.

Shari

Thanks Shari! I went back and inserted your purty chart into the original post so those coming along later can see it right away.

Ray, I didn't copy it to the computer, but I took the same chart I used and added a column for "excess moisture", figured like this (green weight-"dry" weight)/green weight. Some species the numbers matched on, others (ash being the most glaring difference, 30% in my chart vs 15% in your link) were quite a bit different. Yours lists black and white ash, while the UN-L chart just lists green ash, with a seasoned weight almost identical to the black in your chart. Of course the excess moisture chart in your link just says "Ash" to further complicate things.

Man I hate it when something seems simple to explain with a little math, but when you add it all up, it doesn't add up!

Thanks for putting this up Steve.

ray benson said:

There is a similar chart about 3/4's of the way down the page under "Regarding Seasoning of Wood".
http://mb-soft.com/juca/print/firewood.html

Click to expand...

The green chart is what I use too, and have the link on a firewood info sheet I give to my customers at delivery.

Thanks

Thanks for the info--just last night we were discussing the issue--that wood needs to be dry before you burn it! Friends were entertaining us with a smoldering smoky fireplace! They were trying to burn a recently cut down tree!
Ooops.
MIKE

i think alot of what seems right on paper is not necessarily correct in real world findings ,many contradictions ive seen such as cherry and or red oak they are usually sopping squirt you in the eye wet when fresh cut and yet still is charted less moisture than ash.:tapedersonally i dont know how practical the chart really is.

Time of year when cut has a lot to do with it IMO.

Great replies guys, that's the stuff I mentioned that makes it not a simple math equation. When I've run out of seasoned wood in the past, I've burned a lot of birch that was still green. It ranks fairly low on both lists, but it seemed to work OK. Now that my woodpiles are in good shape, it's become more of a firestarter wood, or used on warmer days.

I'd guess that in addition to actual moisture content, the density of the wood will have an affect on drying time as well. Therefore, (just using my numbers for this one) Red Cedar should dry in a hurry, while stuff like the oaks, elms, walnut, etc that are denser with a lot of water should take longer to dry.

Still bigger holes in my theory are at the bottom of the chart, the "junk" woods, like buckeye. I have a stack of buckeye that was cut in June and is popcorn fart dry already, despite having to lose more water weight than the wood weighs dry. I've had very similar experiences with box elder. Maybe the lighter, more open grain allows for really fast drying?

I wonder if the variances in the wood charts don't show a difference in trees growing in different environments in different parts of the country. The chart I used is from U of Nebraska-Lincoln, I guess I'd call NE semi-arid, not desert by any means, but quite a bit dryer than farther east. The Juca chart Ray gave is from the US Forest Products Laboratory in Madison, WI. Not a long ways apart geographically, but a look at an annual rainfall map shows about 4" more annual precip at Madtown, that's fairly significant when dealing with plants that need water to grow.

Just throwing a bunch of stuff out there for y'all to think about while staring out the window waiting for Friday to get done with!

Interesting

The posts here are useful and interesting.
The woods I use for our wb stove, are usually what can be salvaged, or saved from damaged trees or prunings. Naturally here in Jordan, a desert climate we don't have some of the species mentioned.

There is also a government ban on cutting trees--anywhere--without permit. Except on private property. North of Amman, near Jerash and Dibbin are ancient forests that for the most part have been depleted, hence the protection. There are oak, pine and cypress. Even so damaged trees fall--even in my own front yard! I had two or three poplars keel over when the ground was wet. But later discovered they were being attacked by huge worms. At our small farm we have thinned out eucalyptus--usually fallen branches, and cypress, and at one time some acacia that had overgrown the space. Sometimes we get pieces of olive wood that burns very hot once it gets going.

As for the tree our friends were trying to burn--it had fallen on an alleyway, so was probably diseased. It was a deciduous tree of some sort.

Many thanks to everyone here with all the info.
Mike

I cut some hedge around the first of the year. After splitting it tested at 20% for the heartwood and 28% for the outside ring. Normally it tests about 25% for the heartwood and 38% for the outside ring. I guess trees are dryer during the winter.

rmotoman said:

I cut some hedge around the first of the year. After splitting it tested at 20% for the heartwood and 28% for the outside ring. Normally it tests about 25% for the heartwood and 38% for the outside ring. I guess trees are dryer during the winter.

Click to expand...

"Sap down" when cut, will burn better right away than sap up and seasoned for 6 months with some species.

It's one of the reasons I cut mostly in winter. Even if I can't get to them to skid them out, I'll drop them.
That way I can be a bit lazy at the splitter later.

Stay safe!
Dingeryote