If DRYING wood, why let it get wet??!?!?!

  • 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.
Status
Not open for further replies.
Dylan said:
castiron said:
Ok folks......no voodoo or old wives tales.....here's the definitive answer from the Univ of Kentucky College of Agriculture found here:

http://www.ca.uky.edu/agc/pubs/for/for35/for35.htm

"Regardless of the species being dried, the drying process can be speeded up by splitting the wood and stacking it in the open (not next to a wall) so that good air circulation exists around and through the stack, and stacking it in full sunlight to take advantage of solar energy. Cover the top of the stack to protect it from rain and snow. Do not cover the sides as you will cut off the air exchange needed for the wood to dry. Designing a solar collector to maximize the solar energy potential is a great way to dry firewood. Just remember to allow for plenty of air flow through the firewood (Figure 2). "

So, all old wives/fisherman's tales aside....protect it from the rain...LOL


Sounds as though Kentucky gets only perfect weather.

Guys still marry their sisters down there, don't they??


Oregon has damp weather and even they say (on the bottom left hand corner of pg 3 of this link) to cover wood:

http://owic.oregonstate.edu/pubs/for55.pdf
 
I think covering your wood is probably good advice for most people and it's probably what I'd say too if I was writing a how-to piece on the topic. But I also think it's overkill and if you know what you're doing, you don't have to live with a blue tarp dominating your backyard all summer long.

Dylan: Marying your sister is one thing; marrying your daughter--like they do in Connecticut--is a whole nother thing!
 
I do not "dry" my wood. I let it "season". Sounds like if you are trying to "dry" your wood (or lumber), then you'd better cover it.

Ever see an old fence with wooden fence posts? I'm not talking about anything ever bought from a lumber yard, but the posts like they used to use in the old days that were a 6 foot piece cut from a 4-6" diameter tree trunk or limb. We have some (probably black or red oak) that are still holding the fence up after 40-50-60 or more years. Some of them have even outlasted the barbed wire. And those old fence posts were cut green, bark left on them, one end buried in the ground, and the other end pointed right up at the rain. The end in the ground rots off first, after many decades. I'll bet you could cut them up and they'd still burn very well to this day. None of my firewood is buried in the ground and if it lasts a fraction of what those old fence posts have (and they aren't covered either), then I'll be happy.

If covering your firewood makes you feel better, then by all means cover it. Not covering mine works very well for me, but might not work as well for you. I cannot be convinced that covering my woodpile would be anything more than, as Eric put it, a pain in the hind end, no matter how many colleges write papers about it!
:)
 
Dylan said:
Eric Johnson said:
Dylan: Marying your sister is one thing; marrying your daughter--like they do in Connecticut--is a whole nother thing!

I thought we agreed to keep THAT 'under wraps'.

Great wood pile humor!

This horse of a thread is literally just a hide it has been beaten to friggin death...Can we enter it into the cat vs. non cat, husky vs. stihl and soapstone vs. steel category!
 
I think there is a corialis effect from the moisture rising from uncovered wood piles that probably adds to global warming. But on the other side of the equation are the economic gains in China from the sale of all of those blue tarps that last two weeks.

Ya gonna lose either way.
 
BLUE tarps ! WOW do they stand out.
I go to Menards and pick up a fue 10'X20' BROWN plastic tarps as the only place i can find the color. You dont notice the wood pile is covered with a brown tarp and it dont stick out like a sore thumb.
 
Dylan said:
Not sure what your point is, here. Are you suggesting that those who cover their wood should 'season' it instead....for 40-50-60 years.....or that we should stick one end in the ground and point the other end skywards???
Ha ha ha! Yes, that's exactly it! Jeez. :)

You cover your wood and write a paper about it if you want. I'll not cover mine and not write a paper about it. Agreed?
 
I have brown tarps, too. But they're still a pain in the ass.

Apparently, tarp color has something to do with the thickness of the material. The blue stuff is the thinnest and thus the cheapest gauge. Hence the proliferation of blue tarps all over the countryside. Why couldn't they make the cheap ones green or brown?

There's a joke up in Maine about how rural people believe that if you cover something up with a blue tarp....it disappears. Makes nice roofing, too.

Another one of my favorite Maine-based jokes is that if you could buy a bus ticket with food stamps, pretty quick there wouldn't be anybody left in _________[you choose the town].
 
Dylan said:
quads said:
Ever see an old fence with wooden fence posts? I'm not talking about anything ever bought from a lumber yard, but the posts like they used to use in the old days that were a 6 foot piece cut from a 4-6" diameter tree trunk or limb. We have some (probably black or red oak) that are still holding the fence up after 40-50-60 or more years. Some of them have even outlasted the barbed wire. And those old fence posts were cut green, bark left on them, one end buried in the ground, and the other end pointed right up at the rain. The end in the ground rots off first, after many decades. I'll bet you could cut them up and they'd still burn very well to this day. None of my firewood is buried in the ground and if it lasts a fraction of what those old fence posts have (and they aren't covered either), then I'll be happy.

Not sure what your point is, here. Are you suggesting that those who cover their wood should 'season' it instead....for 40-50-60 years.....or that we should stick one end in the ground and point the other end skywards???

Dylan,

her point is this: if a fence post, standing in the open elements for 40 years is not rotted and would, if cut up, most likely burn very well, then she sees no reason to cover wood which will be used in a far shorter time and therefore has even less time to rot.

What she's missing is this: the fence post has 40 years to thoroughly get rid of all it's sap and other non-water components, thus only leaving moisture from periodic rainfalls to get rid of. However, most firewood is usually used with a few years of being cut and to dry it out the fastest you have to cover it. The "apples-to-apples" comparison question to ask is this: take a freshly cut piece of wood and make two fence post-sized objects out of it. Take one and plant it in the ground as a fencepost and put the other in a top-covered only woodpile. Now wait 9 months and do a moisture analysis on both pieces of wood. Bet you anything the one protected from rain has a lower moisture content and burns better than the one that's sat out as a fence post for that same 9-month period! That's what she's missing and two different studies from two varied climate regions (Kentucky and Oregon) prove that it's best to top-cover only your woodpile...... Now....let's get on to that soapstone vs steel and cat vs non-cat discussion!
 
My point is that if you're going to store your wood for a year or more before burning it, you don't need to cover it, because it will dry out just fine exposed for that long to the elements.

One thing that makes a fencepost different from a pile of wood is that the post has full access to an unlimited supply of fresh air. Constant exposure to sunlight and oxygen kills off the mircoorganisms that cause decay. That's not the case in the middle of a poorly-executed wood pile, especially if it's covered with a tarp.
 
castiron said:
What she's missing is this: the fence post has 40 years to thoroughly get rid of all it's sap and other non-water components, thus only leaving moisture from periodic rainfalls to get rid of.

What you are all missing so far is that the fence post was not made from just any tree that happened to be growing nearby, the species is selected for its decay resistance and that can change some depending on the type of ground it will be planted in.

I just cut up a white oak top left from when my land was last logged, about 22 years ago, does not make a lot of flames and is hard to get burning (most of the volatiles have evaporated or washed out) but it makes a real nice coal bed.
______________
Andre' B.
 
Eric Johnson said:
My point is that if you're going to store your wood for a year or more before burning it, you don't need to cover it, because it will dry out just fine exposed for that long to the elements.

One thing that makes a fencepost different from a pile of wood is that the post has full access to an unlimited supply of fresh air. Constant exposure to sunlight and oxygen kills off the mircoorganisms that cause decay. That's not the case in the middle of a poorly-executed wood pile, especially if it's covered with a tarp.

but a fencepost "wicks" water from the ground up and rainwater is pulled down through the top by gravity. Rotting can start within the post, far below the point where germ killing ultra violet rays can reach it. While the same decay could start deep within wood in a wood pile, you're unnecessarily adding water to exposed wood and that increases the drying time.

Put another way: you dry wood to get rid of moisture....why would you therefore want to subject it to more moisture by letting the rain continually pound it...think about it....
 
castiron said:
Eric Johnson said:
My point is that if you're going to store your wood for a year or more before burning it, you don't need to cover it, because it will dry out just fine exposed for that long to the elements.

One thing that makes a fencepost different from a pile of wood is that the post has full access to an unlimited supply of fresh air. Constant exposure to sunlight and oxygen kills off the mircoorganisms that cause decay. That's not the case in the middle of a poorly-executed wood pile, especially if it's covered with a tarp.

but a fencepost "wicks" water from the ground up and rainwater is pulled down through the top by gravity. Rotting can start within the post, far below the point where germ killing ultra violet rays can reach it. While the same decay could start deep within wood in a wood pile, you're unnecessarily adding water to exposed wood and that increases the drying time.

Put another way: you dry wood to get rid of moisture....why would you therefore want to subject it to more moisture by letting the rain continually pound it...think about it....

Well, things are not always what they seem. I think the process of wetting the wood and then having that moisture evaporate actually contributes to thorough drying. When you lick your lips in the winter, they chap. That's because the evaporating surface moisture is drawing the moisture from inside your skin as it evaporates. Putting a sealant like Chapstick on your lips helps retain the moisture. Same deal with driftwood; it dries out pretty quick sitting on the beach, completely exposed to the elements.

If you were concerned about preserving the character of your firewood, then you would want to cover it and keep it covered so that it wouldn't weather. But if you're going to burn it in a year or two, the weathering is not a factor and in fact, it contributes to the drying (seasoning) process, IMO.
 
Dylan said:
Seems to me as tho YOU wrote the paper. My terseness is one of my shortcomings.
Come on in and sit around the fire with a number of colorful characters who, like the Cartalk Guys, can answer ANY question....but don't be surprised if your answer contains a little more than you were asking for!
 
Eric Johnson said:
castiron said:
Eric Johnson said:
My point is that if you're going to store your wood for a year or more before burning it, you don't need to cover it, because it will dry out just fine exposed for that long to the elements.

One thing that makes a fencepost different from a pile of wood is that the post has full access to an unlimited supply of fresh air. Constant exposure to sunlight and oxygen kills off the mircoorganisms that cause decay. That's not the case in the middle of a poorly-executed wood pile, especially if it's covered with a tarp.

but a fencepost "wicks" water from the ground up and rainwater is pulled down through the top by gravity. Rotting can start within the post, far below the point where germ killing ultra violet rays can reach it. While the same decay could start deep within wood in a wood pile, you're unnecessarily adding water to exposed wood and that increases the drying time.

Put another way: you dry wood to get rid of moisture....why would you therefore want to subject it to more moisture by letting the rain continually pound it...think about it....

Well, things are not always what they seem. I think the process of wetting the wood and then having that moisture evaporate actually contributes to thorough drying. When you lick your lips in the winter, they chap. That's because the evaporating surface moisture is drawing the moisture from inside your skin as it evaporates. Putting a sealant like Chapstick on your lips helps retain the moisture. Same deal with driftwood; it dries out pretty quick sitting on the beach, completely exposed to the elements.

If you were concerned about preserving the character of your firewood, then you would want to cover it and keep it covered so that it wouldn't weather. But if you're going to burn it in a year or two, the weathering is not a factor and in fact, it contributes to the drying (seasoning) process, IMO.

Eric,

the two university studies I quoted disagree with you...they're both from the ag colleges, one in KY and one in OR.........

Also, your argument is kinda like the one about what cools or freezes faster, hot water or cold water. People claim that although the goal is drive the temp down and to freeze water, that going in the other direction (heating the water first) will somehow cause it to freeze quicker. What it actually does is cause the water to cool at a faster rate (because of the greater temp between the hot water and the freezer temp) but it actually takes longer to freeze than does the cold water. Similarly with wood: the goal (just like freezing water) is to drive moisture out of the wood and people claim that by going in the opposite direction (exposing wood to additional rainfall) that somehow it dries faster. No way....
 
Eric Johnson said:
Well, things are not always what they seem. I think the process of wetting the wood and then having that moisture evaporate actually contributes to thorough drying. When you lick your lips in the winter, they chap. That's because the evaporating surface moisture is drawing the moisture from inside your skin as it evaporates. Putting a sealant like Chapstick on your lips helps retain the moisture. Same deal with driftwood; it dries out pretty quick sitting on the beach, completely exposed to the elements.

If you were concerned about preserving the character of your firewood, then you would want to cover it and keep it covered so that it wouldn't weather. But if you're going to burn it in a year or two, the weathering is not a factor and in fact, it contributes to the drying (seasoning) process, IMO.

My theory, WAG, is that while the wood is drying the sap makes it's way to the surface where the water evaporates leaving behind the sugars and other minerals which plug up the pores on the surface, your chap stick, making further drying slower. A good rain can wash that coating off. Around here Wis. even after a 3 day rain you can get a nice clear day and by noon the wood pile is back to where you started before the rain, that is not true for all locations, like the NW coast.
______________
Andre' B.
 
True dat, Andre.

I don't know what to tell you, cast. I've been cutting, drying and burning firewood for more than 30 years and not covering the pile has always worked well for me. Like quads said, cover your wood if it makes you happy. I know the Chinese tarp purveyors are happy to help you out.

As it happens in the real world, the top course or two of chunks gets all the rain anyway, and they're the first ones to dry out when the sun comes back out. The stuff below that stays dry, even in the hardest rain storm.
 
I'm beginning to think that the true answer is that the difference in drying/seasoning times between covered and uncovered piles is so inconsequential that unless one is operating in a controlled, laboratory environment we can't measure the drying rate differences. Its apparent that each method has it's true believers, therefore both methods most likely work just fine. So I vote if covering floats your boat, go for it. If going au-natural is more your thing, that's cool too baby!
 
Eric Johnson said:
As it happens in the real world, the top course or two of chunks gets all the rain anyway, and they're the first ones to dry out when the sun comes back out. The stuff below that stays dry, even in the hardest rain storm.
Exactly Eric! And here's a picture of a portion of my woodpile after three days straight of rain, 2 inches of it. The lower 2/3 is not even wet, and it was still raining when I snapped the picture. http://img.photobucket.com/albums/v604/quads/drying-wood.jpg

Furthermore, if you were to split the "wet" ones, you would not find any rainwater on the inside. Only on the surface, and the surface moisture does not concern me, only the inside. Rainwater does not soak through the wood, only the surface. Otherwise, they would have never been able to use wood shingles in the old days. The rain would have came straight through them and into the house, by that logic.

Like I said before, cover your wood if it makes you feel better. Does not matter to me one way or the other. But, I cannot be convinced that it would be worth my while to cover my wood for 4+ years before I actually burn it.
:)
 
quads said:
Eric Johnson said:
As it happens in the real world, the top course or two of chunks gets all the rain anyway, and they're the first ones to dry out when the sun comes back out. The stuff below that stays dry, even in the hardest rain storm.
Exactly Eric! And here's a picture of a portion of my woodpile after three days straight of rain, 2 inches of it. The lower 2/3 is not even wet, and it was still raining when I snapped the picture. http://img.photobucket.com/albums/v604/quads/drying-wood.jpg

Furthermore, if you were to split the "wet" ones, you would not find any rainwater on the inside. Only on the surface, and the surface moisture does not concern me, only the inside. Rainwater does not soak through the wood, only the surface. Otherwise, they would have never been able to use wood shingles in the old days. The rain would have came straight through them and into the house, by that logic.

Like I said before, cover your wood if it makes you feel better. Does not matter to me one way or the other. But, I cannot be convinced that it would be worth my while to cover my wood for 4+ years before I actually burn it.
:)

All I'm saying is that if the goal is to extract moisture OUT of the wood that you don't reach your goal more quickly by allowing MORE moisture in...........it doesn't work that way when you're trying to freeze water and it doesn't work that way when you're trying to dry wood........ :bug:
 
Alright, here's the deal:

There's been a lot more reseach into air drying lumber than drying firewood. And what the lumber experts say is that the most important factors in air drying lumber are ambient temp and ambient humidity. And the most important contributor to drying lumber outdoors is what they call the chimney effect which, as you might suspect, involves convection. Hot air rises out the top of the stack of lumber, drawing cooler, moist air with it. You can't have a chimney effect if you block the chimney, which what you risk doing when you tarp a stack of wood. No convection means stagnant air, which means no drying.

The U.S. Forest Service has done extensive research on this and the results are available on the internet through the Forest Products Lab in Madison, WI.

I'm sure if you read the literature, cast, you'll gleefully note that the stacks of lumber are covered with makeshift roofs. However, you'll also note that instead of sitting right on top of the lumber, they are jacked up about 6 inches from the top course, so as to allow the chimney effect to work. And if you read closely, you'll note that the main reason for the cover is to protect the top courses from the detrimental effects of direct sunlight.

As quads so aptly points out, surface water is inconsequential with firewood. Here today; gone tomorrow. The real challenge in drying any wood--firewood or lumber--is to get rid of the "bound" water, which is the water that exists in the cell walls. That takes months of exposure to the elements to work its way out of the wood. You won't dispense with bound water in a stagnant air environmnent, but you will do it very efficiently with the chimney effect.

Bottom line: your wood will dry quicker if you cover it, but only if you cover it correctly. Throwing a tarp over the top and tying it down to the sides is the wrong way to do it, and your wood probably will not dry as quickly as a result. That's what makes woodsheds such a good idea.
 
Eric Johnson said:
Alright, here's the deal:

There's been a lot more reseach into air drying lumber than drying firewood. And what the lumber experts say is that the most important factors in air drying lumber are ambient temp and ambient humidity. And the most important contributor to drying lumber outdoors is what they call the chimney effect which, as you might suspect, involves convection. Hot air rises out the top of the stack of lumber, drawing cooler, moist air with it. You can't have a chimney effect if you block the chimney, which what you risk doing when you tarp a stack of wood. No convection means stagnant air, which means no drying.

The U.S. Forest Service has done extensive research on this and the results are available on the internet through the Forest Products Lab in Madison, WI.

I'm sure if you read the literature, cast, you'll gleefully note that the stacks of lumber are covered with makeshift roofs. However, you'll also note that instead of sitting right on top of the lumber, they are jacked up about 6 inches from the top course, so as to allow the chimney effect to work. And if you read closely, you'll note that the main reason for the cover is to protect the top courses from the detrimental effects of direct sunlight.

As quads so aptly points out, surface water is inconsequential with firewood. Here today; gone tomorrow. The real challenge in drying any wood--firewood or lumber--is to get rid of the "bound" water, which is the water that exists in the cell walls. That takes months of exposure to the elements to work its way out of the wood. You won't dispense with bound water in a stagnant air environmnent, but you will do it very efficiently with the chimney effect.

Bottom line: your wood will dry quicker if you cover it, but only if you cover it correctly. Throwing a tarp over the top and tying it down to the sides is the wrong way to do it, and your wood probably will not dry as quickly as a result. That's what makes woodsheds such a good idea.

Eric,

I totally agree that the covered section needs to be raised-up as in a lean-to or similar fashion. I have a tarp on mine and plan to do exactly that (lean-to). But it comes down to the same big picture.....you DON'T achieve an end goal of drying wood by subjecting it to rainfall........as to how we shield it (tarp, lean-to, etc) I agree that the raised/covered idea is better but this "rain helps it dry out" stuff I'm hearing doesn't pass the sanity check test....
 
You're missing the big point, cast.

Nobody said wood subjected to rain dries faster. We're saying it's basically an inconsequential piece of the puzzle. Once your wood has dried, a little rain, or even a good soaking, has no long-lasting detrimental effect.

Getting your wood to dry correctly in the first place is the main objective. And if you just throw a tarp over the top and thus restrict the vertical airflow (chimney effect), it will not dry as quickly as if you had left it exposed to the elements.

Do you agree with that?

As a practical matter, most people trying to dry wood will do just that. And as a result, they would be better off not covering it at all.

So you're technically right. But in practice most people are going to botch the job, and then they're going to blame you when they're trying to burn sizzling wood this winter. Do you really want that on your conscience?
 
Status
Not open for further replies.