How much does wood season in the cold of winter?

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DodgyNomad

Minister of Fire
Dec 19, 2009
704
West Michigan
It's been so cold and snowy here this winter. I have about 20 cord split, stacked and covered and wondered how much seasoning occurs when it's averaging 13 degrees for weeks on end?

We've been getting lows around 0 quite often and highs in the low 20's. Is my wood still drying?
 
I would think it is still drying, but subscribing to hear replies
 
i would think any moisture trapped in the wood would be frozen and quite resistant to evaporation (or in this case sublimation). however humidities are very low in the winter. but i think the first trumps the second. so, in my opinion, the answer to your question is very little when compared to wood that isnt frozen solid..
 
I believe the general consensus is that the wood is still seasoning in the sun and wind and open air . . . albeit slowly . . . providing it isn't stuck in middle of a snowbank.

The usual item to illustrate this point . . . for better or for worse . . . is an ice cube left in the freezer for so long that it gets smaller as the ice evaporates.
 
What about freeze drying? I mean as far as the moisture anyway
 
It is really all about moisture. What I have seen in my area (North Carolina), is that my wood will loose moisture faster in the winter months. Cold air is typically drier, and when it passes over the woodpile, it picks up more moisture. However, you do have to consider that my spring and summer may have more humidity than yours, which is why I see faster drying in winter.
 
i would think any moisture trapped in the wood would be frozen and quite resistant to evaporation (or in this case sublimation). however humidities are very low in the winter.

There are solutes in the water inside wood that act as natural antifreeze, so that water doesn't freeze until it gets far below 0C / 32F. That's why trees rarely split from the expansion of freezing water in winter.

Outdoors, only absolute humidity is significantly lower, meaning there's less moisture in a given volume of air. There's less moisture because cold air can't hold as much moisture as warm air can. The properties that keep cold air from taking up water from the ground, snow, etc. also prevent it from absorbing water from a split of wet wood. In other words, even though the absolute humidity is lower in winter, the outdoor *relative* humidity is pretty much the same as it is in summer. That outdoor air feels drier to you as a person, and actually does dry YOU out faster because you are warm, and when your body heat warms the air that's in contact with your skin that causes the relative humidity of that thin layer of air to drop. Of course a pile of wood splits drying in the yard doesn't have an internal heating system and doesn't experience winter air as especially dry.

Even if the water in wood isn't frozen, cold temperatures do slow down its movement through the wood tissues. There's a rule of thumb that wood dries twice as fast for every 20 degree (Fahrenheit) increase in temperature, so if winter temperatures are 40 degrees cooler in winter then drying is only 1/4 as fast. Here's a related post I put together last year.

Of course, if the wood is encased in ice and snow then it isn't going to dry at all.
 
It is really all about moisture. What I have seen in my area (North Carolina), is that my wood will loose moisture faster in the winter months. Cold air is typically drier, and when it passes over the woodpile, it picks up more moisture. However, you do have to consider that my spring and summer may have more humidity than yours, which is why I see faster drying in winter.

yes, but your wood isnt frozen for months on end. much warmer in NC than in MI.

and i will stick to my intial post. logic says the rate of sublimation is less than evaporation in most cases.

to the ice cube analogy- its open to air, not trapped inside wood. again, thats what logic tells me.
 
I think the freeze dry effect happens on or near the surface, but I agree in simple terms the real moisture loss slows down in the cold.

It is interesting to split rounds in winter and bring them inside right away and see how much moisture is in them. 2 days ago I was splitting 14" oak rounds from dead standing oak I cut last winter. I thought it would be dried some. When I brought it in it started sweating, some from condensation I'm sure; it was 5° outside that day. The next day I resplit and tested the moisture. 20%-38% depending on the piece. I suppose the pieces that were on the outside (south) side of the pile did some drying, but the lower or back pieces obviously did not.

It has been below 0°F most nights for the last month, so there is probably very little drying happening in my piles right now.
 
It's been so cold and snowy here this winter. I have about 20 cord split, stacked and covered and wondered how much seasoning occurs when it's averaging 13 degrees for weeks on end?

We've been getting lows around 0 quite often and highs in the low 20's. Is my wood still drying?

Frozen wood continues "seasoning" just fine in the winter (because "seasoning" doesn't mean anything). It continues drying as well, just very slowly.

Think of a pair of soaked jeans. On a hot summer day they'll dry in a few hours on a clothes line. In the middle of winter they can hang for a week and not be dry, though the MC will undoubtedly be lower after that week.
 
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Mine isn't drying to fast this winter as most of my stacks are buried in the snow. We have had so much wind and snow that my stacks are just big snow drifts
 
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It's been so cold and snowy here this winter. I have about 20 cord split, stacked and covered and wondered how much seasoning occurs when it's averaging 13 degrees for weeks on end?

We've been getting lows around 0 quite often and highs in the low 20's. Is my wood still drying?
the rate of sublimation on a very cold dry ( wind always helps things along) is often higher than the non-rate of evaporation on one of those soupy 100% humidity days of Summer

Just put some towels or denim jeans on a line and watch what happens.

You'll need bar clamps to try it with splits.

You'll get faster and measurable results with textiles vs raw wood fibre.
 
I have zero to offer from an input standpoint, but thanks to the OP for starting this thread as I've been very curious about the same thing and I'm eager to learn.
 
Very simply put; ice cubes in you freezer will evaporate and so will the moisture in you split fire wood, although at a slower rate and as long as it's not buried in snow banks.
 
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This according to Vermont Wood Utilization Fact Sheet:

Before using air dried lumber (±15% moisture content) indoors,the lumber should be kiln dried or stored inside a heated building until t he moisture content aver ages 8 %. The period of time required to air dry lumber in Vermont to an average moisture content of 15 to 20% varies considerably with the weather and species being dried. Very little drying occurs during the winter, when the lumber is frozen, or during damp rainy weather. In general, one inch lumber will air dry (15 to 20% moisture content) in 45 to 60 days of warm, dry weather. Two inch lumber may take as much as 90 days under similar conditions.

Measuring Moisture Content of Lumber.

The actual moisture content of air dried lumber should always be checked prior to use. The moisture content of a piece of lumber can be determined by several methods, but the two most common of these are by the use of an electronic moisture meter or by weight. Moisture meters are available through most lumber yards and woodworkers supply stores. To determine the moisture content of a board without a moisture meter, the oven drying method can be
used. Moisture content is determined by cutting a cross section of a board, weighing the section accurately, drying the sample completely (roughly 12 hours at about 200 F), and re-weighing the sample.


This was put together for lumber not firewood but still. I saw somewhere where they provided a table with avg drying by month but I can't locate right now. Dec, Jan & Feb were worst. As I recall drying was negligible at those times which surprised me a bit given the often low humidity during winter months.
 
Frozen wood continues "seasoning" just fine in the winter (because "seasoning" doesn't mean anything). It continues drying as well, just very slowly.

Think of a pair of soaked jeans. On a hot summer day they'll dry in a few hours on a clothes line. In the middle of winter they can hang for a week and not be dry, though the MC will undoubtedly be lower after that week.

Various dictionaries disagree.

Webster's:
2season
verb: to make (wood) ready for use by slowly drying it

Dictionary.com:
verb(used with object)

11. to mature, ripen, or condition by exposure to suitable conditions or treatment: a writer seasoned by experience.

12. to dry or otherwise treat (lumber)


Anyways, yes your wood still dries, but more slowly. I imagine it dries especially slower if you live in an area that gets a lot of snow. Even when its freezing down here, there's rarely any snow, so my stack are still fully exposed to sun and wind. If your stacks are buried in snow and ice for months at a time, that may effect the seasoning process more than just cold weather.
 
Very simply put; ice cubes in you freezer will evaporate and so will the moisture in you split fire wood, although at a slower rate and as long as it's not buried in snow banks.

Bugger! You beat me to it! It's called the process of sublimation. The ice cubes in the freezer shrinking is a perfect analogy/visual. All be it, the drying process does take a bit longer!
 
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Good thoughts and info, thanks.

And seasoning is the generic term used by most everyone around here for drying/aging of wood. Word Nazi's.
 
I think you misread my post, Im on your side ;lol;)

I'm only kidding, not directed towards anyone in particular, no worries. Just found it funny, as most everyone uses the term seasoning around here.
 
My hypotheses is that there is slight drying in winter. But Wood cut and stacked in the fall will be far dryer than wood cut and stacked in the following early spring before they start sucking water. This is because the single digit freezing of the wood splits the fibers and cells allowing for the water to leave faster in the summer. No facts to back this up, just my thought.
 
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My hypotheses is that there is slight drying in winter. But Wood cut and stacked in the fall will be far dryer than wood cut and stacked in the following early spring before they start sucking water. This is because the single digit freezing of the wood splits the fibers and cells allowing for the water to leave faster in the summer. No facts to back this up, just my thought.
That's an interesting thought.

The only thing is though, wouldn't the cells/fibers have gone through that splitting process while the tree was still yet UNCUT and split? If in fact that process occurs at all.

But, still good theory, and may have SOME validity. Not sure.
 
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I processed some red oak in late November, getting it all stacked up in early December. On Dec 9th I resplit one piece, weighed both parts, left one outside and put one by the fire. The inside piece started at 4133gm and now weighs 2750gm for a loss of about 33% of its original weight. The outside piece, which I kept covered and was on top of my stack, was a little smaller, starting at 3315gm and now coincidentally weighs exactly the same as the inside piece at 2750gm for a loss of 17% of its original weight. Those percentages are of its original weight, not the moisture content.

So my conclusion based on one sample piece is that you can achieve a good deal of drying during the winter.

The inside piece feels dry by its heft. It has sat on the hearth for two months, at times it's surface temp was 130 degrees. If the original moisture content of this wood was 80% the inside would now be at 20% and the outside would be at 49%.
 
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It does dry in the winter , and when the moisture in the wood freezes it splits a little and allows more exposure to heat wind, therfore seasons.- Thats my story and Im sticking to it.. bottom line is time. Get ahead and don.t wory about it.
 
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