What is the Real Definition of Dry Wood?

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I burn everything green in my outdoor wood furnace. mostly maple with some oak and yellow birch mixed in.
One of these years I am going to get ahead and have a load split up and seasoned for the following winter. I wonder how much less wood I will burn letting it season 1 year vs. burning it right off the log truck?
 
bwalker said:
I burn everything green in my outdoor wood furnace. mostly maple with some oak and yellow birch mixed in.
One of these years I am going to get ahead and have a load split up and seasoned for the following winter. I wonder how much less wood I will burn letting it season 1 year vs. burning it right off the log truck?

I've read that you loose about 10% of the heating value driving off the moisture in green wood. Obviously that varies among species of wood. One thing I know for sure, it's tough to burn green red oak.
 
Here we go...this is the truth, whole truth, and nothing but the truth.
WoodsmanYankee Woodlot

University of Maine Cooperative Extension
Bulletin #7116

Heating with Wood the "Lazy" Way: Plan Ahead!

It’s almost May. Now that the weather has turned warmer and the black flies have become friendly again, I can forget about firewood until October, or maybe even November. When it turns colder, and my wife, Lou, begins threatening to turn on the electric heat, I’ll start thinking about firewood again. I’ve always been that way. When we don’t need the heat, I don’t worry about the firewood.

If you would like to become a lazy tightwad about firewood, it's not too late to start.

My traditional reaction to the electric heat threat was to go find the chain saw, get it back into operating condition, and cut some wood. Then split it and get it into the basement. In a week or 10 days, when we were down to a few sticks, I’d repeat the whole ghastly process.

We always had wet wood that was hard to light. It didn’t really produce much heat, so we had to use more of it. We had smoky fires that coated the inside of the chimney with creosote and dribbled black goo from the stovepipe onto the floor. We had one real dandy of a chimney fire that filled the house with smoke and drove us out. Fortunately, the chimney was new and well made, so it didn’t set fire to the house. In short, burning wood was a messy, inconvenient and even dangerous proposition.

If you start drying your wood for next year this spring, it's like getting an extra cord free for every five cords.

Then, one winter, someone was moving, and I got a tremendous bargain on several cords of DRY hardwood. That winter, the things that I’d always known to be theoretically true were proved. The dry wood burned cleanly with little or no smoke. We didn’t get creosote in the chimney or gooey dribbles on the floor. The wood was easy to light and burned hotter: less wood made more heat. Life was good.

I’ve already admitted to being lazy, but I’m also a tightwad: Scottish by heritage and Yankee by inclination. If I can get a return of 18 percent (see Table 1) on my investment of time, labor and money by burning dry wood, that sounds like a good idea. So I’ve rearranged some of my priorities.

Table 1: Heating Values of Wood Based on Moisture Content
Percent of Moisture Percent of Usable Heat
0 (oven dry)

103.4

4
102.7
20 (air-dried hardwood) 100.0
40 96.5
80 89.7
100 (green hardwood)

85.0

Note: 100% (dry) - 85% (green) ÷ 85% = .176 = approximately 18%



Table 2: Approximate Weight and Heating Value Per Cord (80 cu. ft.) of Different Woods, Green and Air Dry (Approximately 20 Percent Moisture Content)
Wood Green Air Dry
Weight
in Pounds Weight
in Pounds Available Heat, Million BTU1 Equivalent in Gallons of Fuel Oil2
Ash 3,840 3,400 20.0 204
Aspen 3,440 2,160 12.5 128
Beech, American 4,320 3,760 21.8 222
Birch, yellow 4,560 3,680 21.3 217
Maple, red 4,000 3,200 18.6 190
Maple, sugar 4,480 3,680 21.3 217
Oak, red 5,120 3,680 21.3 217
Oak, white 5,040 3,920 22.7 232
Pine, eastern white 2,880 2,080 12.0

123



Table 3: Approximate Stacked

Volume of a Cord of Wood, Cut and Split
Length Approximate
Cubic Feet Approx. Percent
Shrinkage from 128 Cubic Feet
48" 128 0
24" 110-113 12
16" 103-107 16
12" 100-103 20


I’m still not going to worry about firewood until October or November. That’s because the wood for next winter was cut, split and piled in the woodshed a year ago, and I’ve just finished putting up wood for the winter after next. When we need it, all I’ll have to do is bring it in. It will be clean and dry and safe to burn. Maybe best of all, I won’t be out in the howling blizzard in the dead of night trying to get enough wood to stay warm for a few days. All of that's enough to make a lazy man smile.

If you would like to become a "lazy tightwad" about firewood, it’s not too late to start. If you put up your wood for next winter in April, it should dry to a moisture content of 25 to 30 percent by the time you need it. At this moisture level, it will burn pretty well, much better than green. Try to pile it off the ground (used pallets are free and work nicely) in the sun and cover the top . Don’t cover the sides of the pile. You want air to move through. If you can get two years ahead, you will have wood at about a 13 to 15 percent moisture content. Burning wood this dry is almost a luxury and is what prompted me to build my woodshed.

More Firewood Laziness

When I wrote the above article for Cooperative Extension's newsletter, Maine Farms and Forests, my neighbor hadn’t moved away yet. He’s the neighbor who owned the hydraulic wood-splitter. Since he was long on money to buy toys and short on mechanical aptitude, and I am the exact opposite, we had a wonderful relationship. I kept his machinery serviced and running in exchange for the privilege of using it.

Anyway, he moved away and took his splitter with him. So I found myself doing something that I haven’t done for years — splitting wood with a maul. Remember, I’m a tightwad and wouldn’t even consider hiring a splitter, let alone buying one! If you’re not with me on this, you might as well skip the rest of this fact sheet, since we’re not on the same wavelength.

Wood Splitting the Old Way

A thrown cord of 12- or 16- inch wood will occupy 52 more cubic feet of space than a stacked cord of wood.

First, I place a chunk of wood on the chopping block and deliver a mighty swing of the maul. One of two things happens: 1) the wood splits into two pieces, each of which fly in opposite directions, and I have to chase them for the next split or to throw them onto the pile, or 2) it doesn’t split and promptly falls off the chopping block, so I have to pick it up and put it back before trying again. Either way, this represents too much wasted work for me!

An old ATV tire is fastened with wood screws to the top of a chopping block. Wood to be split is placed inside the tire.
An old ATV tire is fastened with wood screws to the top of a chopping block. Wood to be split is placed inside the tire.

Wood Splitting the Lazy Way

My attempts to ease my work load finally led to the following acceptable solution. I got a big, worn-out ATV tire about 14 inches wide and about two feet in diameter. It was free from a dealer who would have had to pay to get rid of it. I cut out most of both sidewalls with tin-snips and fastened it to the top of my chopping block with wood screws and big fender washers (see drawing above).

Now, when I get ready to split wood, I place it inside the tire, on top of the chopping block. This is very effective in keeping the chunk of wood on top of the chopping block, where it belongs. It also provides three additional benefits that I had not expected:

1.

When the maul comes down, it is trapped inside the tire so there is no danger of chopping your foot.
2.

The maul compresses the tire on the downswing, which in turn lifts the maul out of the split.
3.

If you just drop the maul inside the tire while you are doing something else, it will stand up on its head, right where you can get it without bending over.
4.

Another thing (which I hate to admit) is that I purchased a pulpwood tong for picking up the wood and putting it onto the chopping block. This extends my reach and, thus, reduces bending. The tong "puts a handle" on the wood, which lets me pick it up with one hand. I also bought a belt holster for the thing so it’s always handy, and so I don’t have to bend over to get it. These are available from chainsaw dealers. They are well worth the investment, and that's the opinion of a tightwad!



Pulpwood Tong
Pulpwood Tong

Facts for People Who Heat with Wood

Fact 1: Did you know that if you start with a cord of wood, cut it to shorter lengths, split it and then repile it, the original cord will shrink? The same amount of wood (less a little sawdust) will occupy less space. Table 3 shows how wood stacks up when cut and split.

Fact 2: Different kinds of wood have different weights and fuel values. Table 2 shows some relative values.

Fact 3: A "thrown" cord of 12- or 16-inch wood will occupy 52 more cubic feet of space than a stacked cord of wood.

Prepared by Jim Philip, Extension forestry specialist, wood technology

For more information, contact your University of Maine Cooperative Extension county office.

Published and distributed in furtherance of Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the state of Maine and the U.S. Department of Agriculture cooperating. Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.


Return to Publications Catalog Online Table of Contents
Return to Publications Homepage

Putting knowledge to work with the people of Maine

The University of Maine Cooperative Extension logo

A Member of the University of Maine System
Last Modified: 03/01/06
These pages are currently being maintained from the
Communications Office, University of Maine Cooperative Extension.
Send comments, suggestions or inquiries to [email protected]
 
I just finished splitting and stacking wood for the winter after next and beyond. I only use about 3 cords a year for my log home in KY. It is nice to burn really dry wood. I don't envy you guys up north with the outdoor boilers to feed. I think I'd rather feed another child instead. The boiler doesn't have to go to college though.

If I get bored or need wood I can work on the pin oaks in the second picture (these are on my property). The bigger ones will bury a 36" bar with ease. There are some even bigger diameter ones laying about 100' away, no picture though.
 
Firewood

Big Woody, those logs would keep longer (years) if you knock the loose bark off. Leaving the loose bark on gives the bugs a place to hide and live. They poop all over under the bark and this frass and poop holds moisture that then give fungi a place to live and the moisture to live. Remove the bark that is loose and the woodpile will last years longer out in the weather. The other thing is the wood will not have all the dust on the out side so it will be cleaner to handle carring it in the house.
Then next time you move the logs lay a couple of 12" dia. logs about 20' long, down first and roll your big logs on top to keep them off the ground. The weight will bury the small logs while keeping the larger ones off the ground making them easier to cut later. Off the ground and out of the dirt. That makes it easier on the chainsaw later, keeps you're saw out of the dirt. The chain will stay cleaner longer.
It makes a world of difference if the bark is knocked off as it loosens up, it gives the log a chance to dry out faster and stay dry longer.
 
Seems to me there is no more variable a subject than heating with wood. From types of stoves, chimney draft, kind of wood and whether it is at its peak time for burning. I just use the "feel" test. I have mostly oak, cherry and maple to burn. After cutting, splitting, stacking and generally handling it a bunch of times, I can smell and feel the weight of wood that is asking to go next. Its the same as knowing whether you need to give more air and rake and empty the ashes. I like mixing woods for different temps and days and nights. Best wood I've used was osage orange.
I guess that's another good thing about wood heat, you get allot of practice figuring what works best for your needs because winter lasts awhile.
My wife said along time ago that heating with wood is really a way of life. She's right... I'm a damn slave to that stove but the oilman ain't comin this year. And I probably spent more on saws than I should but hell, its fun.
Woojr
 
What woojr said !. And i ain't seen the propane guy since Sept 1st. And everything in my house is propane,hot water,stove,dryer, and furnace.
 
Impressed

Wow. You guys elevate b.s. to an art level. Really interesting seeing who really knows what they are talking about and who baffles with b.s. This thread has been very entertaining. We sell kiln dried firewood to restaurants for cooking year round. Want to learn more about MC? Go to the Wood Web and pick out a thread and learn and then reread this thread and you too will be entertained.
 
I've been thinking about offering kiln dried firewood. What kind of kiln set-up do you have? How long does it take on average? What do you estimate your energy costs to be per cord for drying?
 
Just curious Schultzz, what is the ideal MC for the products you sell? I can certainly see the food industry having strict standards for use in flavoring etc.
Do you make chunks or smaller chips? What kind of woods are most popular?
I barbeque with store bought mesquite and hickory. Mostly I presoak the chips or chunks a couple hours before using them, but I'm just a backyard bbq guy not a Lone Star. Heck, here's some real BS... I even cook in the stove. Oak does a nice job with beef... couple minutes at 8-9 hundred degrees in there is all it takes.
Thanks allot for Woodweb... allot of great info. But it really doesn't take a scientific study to figure out which wood to put in first. Or, when to put it in, just a little common sense and practice.
 
Mc

woojr said:
Just curious Schultzz, what is the ideal MC for the products you sell? I can certainly see the food industry having strict standards for use in flavoring etc.
Do you make chunks or smaller chips? What kind of woods are most popular?
I barbeque with store bought mesquite and hickory. Mostly I presoak the chips or chunks a couple hours before using them, but I'm just a backyard bbq guy not a Lone Star. Heck, here's some real BS... I even cook in the stove. Oak does a nice job with beef... couple minutes at 8-9 hundred degrees in there is all it takes.
Thanks allot for Woodweb... allot of great info. But it really doesn't take a scientific study to figure out which wood to put in first. Or, when to put it in, just a little common sense and practice.

We sell red and white oak and hickory at 7-10% MC. The best French Chefs cook the best Gourmet meals using wood so you are in good company. Your beef dish sounds great. Keep up the creative touch!
 
Kiln

Newfie said:
I've been thinking about offering kiln dried firewood. What kind of kiln set-up do you have? How long does it take on average? What do you estimate your energy costs to be per cord for drying?

Hi Newf,
Our kiln is homemade from rough cut lumber, lined with salvaged tin (old steel garage door parts), insulated with sawdust in between plastic vapor barriers, and heated with wood scraps. (Cant pieces, firewood rejects, edgings from our pallet mill. Aside from labor (the dragon must be fed every 3-4 hours, the energy costs are very low. We use squirrel cage fans to blow over hot double barrel drums (Vogelzang Kit - Northern Tool), which are encased in a tin box - (Big Box). The fans draw little amperage. It costs pennies to dry the wood, we just dried 5 cords down to 7-10% mc in about 32 hours. Kiln dried wood leaves very little creosote, burns very hot, contains no bugs or larvae, and commands a higher price. $400 and up per cord is not uncommon.
The restaurants love the quality and consistency of the wood. The customers rave over the pizza cooked with this wood. Let me know if I can be of further help.
 
Wood Size

woojr said:
Hi again Schultzz,
What is the average size of the wood put into the kiln? Thanks, woojr

We stack the wood on steel carts. They have 6 casters and are 7 feet long and 32" wide. Our wood comes in already cut and split. It varies between 16 inches to 20 inches long. We bundle the wood with a Twister Wrapper. It stays cleaner and makes for a better presentation, also whoever brings the wood in appreciates the bundles. The wood leaves very little ash so the wood oven doesn't need cleaned out as often. The type of furnace we built can be used to heat treat pallets or slow cure lumber. It just takes finn:clap: :cheers: esse and a long learning curve.
 
hey schultzz-
you're right down the road from me!! I am in BF. I didn't realize there was someone in the beaver valley that kiln dried wood. very nice!
 
It's the idiosyncrasies of wood that intrigues me the most. Granted, there is a chronological order to the way that wood loses it's MC and becomes burnable, but it's those other variables that interest me the most. Not from a commercial standpoint, but rather from my own observations about wood and burning it that I have made over the last 25 years working in the woods.

I find it interesting that the wood that gives off the most BTU's grows in the warmest climates, while the coldest climates have mostly conifers and poplars.
Could plant life and wildlife be an indication of imminent climate change?

Anyway, enough of the professor BS.

I find it interesting to note that wood cut in subzero temps such as -15 C, will literally burn readily with no drying time. I deduce this to the fact that the colder it is the farther the MC is driven into the roots, thus protecting the tree from shattering, which can still happen with a sudden drop in temp.
John
 
Here we go...this is the truth, whole truth, and nothing but the truth.
WoodsmanYankee Woodlot

University of Maine Cooperative Extension
Bulletin #7116

Heating with Wood the "Lazy" Way: Plan Ahead!

It’s almost May. Now that the weather has turned warmer and the black flies have become friendly again, I can forget about firewood until October, or maybe even November. When it turns colder, and my wife, Lou, begins threatening to turn on the electric heat, I’ll start thinking about firewood again. I’ve always been that way. When we don’t need the heat, I don’t worry about the firewood.

If you would like to become a lazy tightwad about firewood, it's not too late to start.

My traditional reaction to the electric heat threat was to go find the chain saw, get it back into operating condition, and cut some wood. Then split it and get it into the basement. In a week or 10 days, when we were down to a few sticks, I’d repeat the whole ghastly process.

We always had wet wood that was hard to light. It didn’t really produce much heat, so we had to use more of it. We had smoky fires that coated the inside of the chimney with creosote and dribbled black goo from the stovepipe onto the floor. We had one real dandy of a chimney fire that filled the house with smoke and drove us out. Fortunately, the chimney was new and well made, so it didn’t set fire to the house. In short, burning wood was a messy, inconvenient and even dangerous proposition.

If you start drying your wood for next year this spring, it's like getting an extra cord free for every five cords.

Then, one winter, someone was moving, and I got a tremendous bargain on several cords of DRY hardwood. That winter, the things that I’d always known to be theoretically true were proved. The dry wood burned cleanly with little or no smoke. We didn’t get creosote in the chimney or gooey dribbles on the floor. The wood was easy to light and burned hotter: less wood made more heat. Life was good.

I’ve already admitted to being lazy, but I’m also a tightwad: Scottish by heritage and Yankee by inclination. If I can get a return of 18 percent (see Table 1) on my investment of time, labor and money by burning dry wood, that sounds like a good idea. So I’ve rearranged some of my priorities.

Table 1: Heating Values of Wood Based on Moisture Content
Percent of Moisture Percent of Usable Heat
0 (oven dry)

103.4

4
102.7
20 (air-dried hardwood) 100.0
40 96.5
80 89.7
100 (green hardwood)

85.0

Note: 100% (dry) - 85% (green) ÷ 85% = .176 = approximately 18%



Table 2: Approximate Weight and Heating Value Per Cord (80 cu. ft.) of Different Woods, Green and Air Dry (Approximately 20 Percent Moisture Content)
Wood Green Air Dry
Weight
in Pounds Weight
in Pounds Available Heat, Million BTU1 Equivalent in Gallons of Fuel Oil2
Ash 3,840 3,400 20.0 204
Aspen 3,440 2,160 12.5 128
Beech, American 4,320 3,760 21.8 222
Birch, yellow 4,560 3,680 21.3 217
Maple, red 4,000 3,200 18.6 190
Maple, sugar 4,480 3,680 21.3 217
Oak, red 5,120 3,680 21.3 217
Oak, white 5,040 3,920 22.7 232
Pine, eastern white 2,880 2,080 12.0

123



Table 3: Approximate Stacked

Volume of a Cord of Wood, Cut and Split
Length Approximate
Cubic Feet Approx. Percent
Shrinkage from 128 Cubic Feet
48" 128 0
24" 110-113 12
16" 103-107 16
12" 100-103 20


I’m still not going to worry about firewood until October or November. That’s because the wood for next winter was cut, split and piled in the woodshed a year ago, and I’ve just finished putting up wood for the winter after next. When we need it, all I’ll have to do is bring it in. It will be clean and dry and safe to burn. Maybe best of all, I won’t be out in the howling blizzard in the dead of night trying to get enough wood to stay warm for a few days. All of that's enough to make a lazy man smile.

If you would like to become a "lazy tightwad" about firewood, it’s not too late to start. If you put up your wood for next winter in April, it should dry to a moisture content of 25 to 30 percent by the time you need it. At this moisture level, it will burn pretty well, much better than green. Try to pile it off the ground (used pallets are free and work nicely) in the sun and cover the top . Don’t cover the sides of the pile. You want air to move through. If you can get two years ahead, you will have wood at about a 13 to 15 percent moisture content. Burning wood this dry is almost a luxury and is what prompted me to build my woodshed.

More Firewood Laziness

When I wrote the above article for Cooperative Extension's newsletter, Maine Farms and Forests, my neighbor hadn’t moved away yet. He’s the neighbor who owned the hydraulic wood-splitter. Since he was long on money to buy toys and short on mechanical aptitude, and I am the exact opposite, we had a wonderful relationship. I kept his machinery serviced and running in exchange for the privilege of using it.

Anyway, he moved away and took his splitter with him. So I found myself doing something that I haven’t done for years — splitting wood with a maul. Remember, I’m a tightwad and wouldn’t even consider hiring a splitter, let alone buying one! If you’re not with me on this, you might as well skip the rest of this fact sheet, since we’re not on the same wavelength.

Wood Splitting the Old Way

A thrown cord of 12- or 16- inch wood will occupy 52 more cubic feet of space than a stacked cord of wood.

First, I place a chunk of wood on the chopping block and deliver a mighty swing of the maul. One of two things happens: 1) the wood splits into two pieces, each of which fly in opposite directions, and I have to chase them for the next split or to throw them onto the pile, or 2) it doesn’t split and promptly falls off the chopping block, so I have to pick it up and put it back before trying again. Either way, this represents too much wasted work for me!

An old ATV tire is fastened with wood screws to the top of a chopping block. Wood to be split is placed inside the tire.
An old ATV tire is fastened with wood screws to the top of a chopping block. Wood to be split is placed inside the tire.

Wood Splitting the Lazy Way

My attempts to ease my work load finally led to the following acceptable solution. I got a big, worn-out ATV tire about 14 inches wide and about two feet in diameter. It was free from a dealer who would have had to pay to get rid of it. I cut out most of both sidewalls with tin-snips and fastened it to the top of my chopping block with wood screws and big fender washers (see drawing above).

Now, when I get ready to split wood, I place it inside the tire, on top of the chopping block. This is very effective in keeping the chunk of wood on top of the chopping block, where it belongs. It also provides three additional benefits that I had not expected:

1.

When the maul comes down, it is trapped inside the tire so there is no danger of chopping your foot.
2.

The maul compresses the tire on the downswing, which in turn lifts the maul out of the split.
3.

If you just drop the maul inside the tire while you are doing something else, it will stand up on its head, right where you can get it without bending over.
4.

Another thing (which I hate to admit) is that I purchased a pulpwood tong for picking up the wood and putting it onto the chopping block. This extends my reach and, thus, reduces bending. The tong "puts a handle" on the wood, which lets me pick it up with one hand. I also bought a belt holster for the thing so it’s always handy, and so I don’t have to bend over to get it. These are available from chainsaw dealers. They are well worth the investment, and that's the opinion of a tightwad!



Pulpwood Tong
Pulpwood Tong

Facts for People Who Heat with Wood

Fact 1: Did you know that if you start with a cord of wood, cut it to shorter lengths, split it and then repile it, the original cord will shrink? The same amount of wood (less a little sawdust) will occupy less space. Table 3 shows how wood stacks up when cut and split.

Fact 2: Different kinds of wood have different weights and fuel values. Table 2 shows some relative values.

Fact 3: A "thrown" cord of 12- or 16-inch wood will occupy 52 more cubic feet of space than a stacked cord of wood.

Prepared by Jim Philip, Extension forestry specialist, wood technology

For more information, contact your University of Maine Cooperative Extension county office.

Published and distributed in furtherance of Acts of Congress of May 8 and June 30, 1914, by the University of Maine Cooperative Extension, the Land Grant University of the state of Maine and the U.S. Department of Agriculture cooperating. Cooperative Extension and other agencies of the U.S.D.A. provide equal opportunities in programs and employment.


Return to Publications Catalog Online Table of Contents
Return to Publications Homepage

Putting knowledge to work with the people of Maine

The University of Maine Cooperative Extension logo

A Member of the University of Maine System
Last Modified: 03/01/06
These pages are currently being maintained from the
Communications Office, University of Maine Cooperative Extension.
Send comments, suggestions or inquiries to [email protected]
Good stuff here.
 
Yes, moldy, oldie, and John's imitation of the BA.

I figure wood is dry when it is at or below 20% moisture content. That is using a cheap moisture meter that is calibrated for Douglas fir, which most are calibrated to. The lowest I have ever measured here was 12% from old 2x4 Doug fir framing in my old garage that was here for 40 years. Generally I can get below 25% moisture in my split conifers here in one summer, with the wood stacked and raised on pallets which are on plastic tarps, and top covered with Firestone rubber roofing removed from the old Portland Coliseum. For oak, maple and alder, it usually takes two seasons to dry. It varies highly from season to season here though, as temps and rainfall varies greatly between years in the PNW.

As for John Ape's observations of higher heat from species of timber growing in warmer climates, that is true to some extent. However, madrone, black locust and white oak grow great here, and this is not that warm a climate. We also have alder, fir, pine and cottonwood that are a lot lower in density and heat value, and it is warmer here than in the Yukon. In California I burned a lot of live oak (most heat of any wood in North America) and Eucalyptus, as well as Monterey pine, alder, madrone and apple. Highly variable in heat values, all grown in a warm place.
 
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