I asked Chat GPT this question—an answer to a debate that has been discussed several times here before: “Why does firewood season faster after it’s been wet and then goes through a drying off process several times?” ANSWER: That’s a great observation. The reason firewood often seasons faster after going through wet–dry cycles comes down to the way wood’s cellular structure responds to moisture: Cell wall breakdown – When wood gets saturated, the fibers swell. As it dries, they shrink again. Repeated swelling and shrinking weakens the cell walls, opens micro-cracks, and increases the surface area where water vapor can escape the next time it dries. Checks and splits – Wet–dry cycling encourages small cracks to form, especially on the ends. These “checks” make more pathways for internal moisture to reach the air, speeding seasoning. Capillary disruption – In fresh or dense wood, water is bound tightly inside cell cavities and capillaries. Repeated cycles can break some of those bonds, so water moves out more freely when drying. Surface conditioning – If wood stays continuously wet, mold and fungi can sometimes start breaking down the surface cell layers, making them more porous. While that’s not always desirable, it can contribute to faster drying later. So, paradoxically, the stress of wetting and drying acts like a natural weathering process that helps wood “open up” and lose its moisture more quickly compared to wood that just sits in a steady state drying slowly.
I've wondered about this myself because I've observed it firsthand. I guess this logic also applies to dead and downed wood too, which has also gone through many wet/dry cycles. Top-covered it dries exponentially faster from a wet state than fresh/live cut of the same species.
I guess there is something to leaving it uncovered for a bit then perhaps covering a bit before getting ready to burn it. I know many folks on hear say they do that all the time.
The problem with this theory is when to stop the wetting/drying process. In nature when this happens you see the rotting taking place. The more it goes toward rot, the more useless the wood is. Therefore the will also be less heat given when burning the wood and I have noticed this very thing. Wet then dry a few times seems to do no harm but don't let that continue if you want good firewood. In days of old, when making timbers for building homes and barns, they didn't want to let this happen and that is why today we see beams in old homes and barns that are still strong and not rotted.
I think if it’s gotten to the point of actual rot taking hold its far too excessive. Something more middle of the road would be better. In other words, if your wood goes through several wet/drying cycles its nothing to worry about but may actually help it season faster. Where I live this process can happen several times in a single month over the summer. Then you can get it covered and put in your shed.
I recall a similar thread being posted about someone spraying their stacks/piles with a hose to accomplish this. I have kinda witnessed this in some of my stacks.
I personally prefer to get my wood CSS ASAP especially in the warm weather before fungi/mold etc. take residence. Most of my stacks are in the shade so I top cover and keep it like that.
I have always tried (not always successfully) to keep my firewood Dry. It just doesn’t make any logical sense to me, to let wood get wet, then dry out again. Doing that, you are not only trying to remove the original moisture, but then removing additional moisture as well, so you are trying to remove even more total moisture than if you kept the wood dry to begin with. To me, this is like the old wives tale that Hot water freezes faster than cold water. Same principle, the hot water may lose heat faster, UNTIL It reaches the same temperature as the originally cold water, then they react the same. BTW, the Hot water freezing faster myth has been debunked by MIT Where we live, top covering isn’t optional, if we left our wood exposed to the weather, it would become Junk, and never be burnable, the only exception being wood CSS in early July, and burned by the end of September, seeing little to no rain. Left in uncovered stacks for a year or more, you just wasted a lot of effort and good wood Just my thoughts, YMMV Doug
Well, I’m not advocating for hosing your stacks down. Mother Nature does that for me. I was just hoping to provide a logical explanation for what many, including myself, have experienced and observed over the years. The only sticking point I would have with the AI answer is point #4 of its answer to my original question. I was proposing a wetting then drying out cycle scenario, not continual wetness.
Then there is the recognition of some AI suffering some sort of “hallucinating” where upon answers may not be 100% accurate. Look it up.
Some of you guys don’t need to top cover, which for me is incomprehensible, we get 90% of our precipitation from mid October through mid May, with only 3% or less in July and August. We don’t get the dry hard freezes in the winter that some of you do, our winter temperatures are typically mid 30’s- low 50’s, we do get some freezing temperatures and snow, but mid 20’s into the teens, is our typical “Cold” temps, and those temps and snow typically only last a few days, not extended periods of very cold weather. We’re on the WE(s)T side of the Cascades, the Eastern side is in the rain shadow of the Cascades, and is Higher and drier than we are, the Cascades also block the Marine influence of the Pacific Ocean, which tends to moderate our temps, highs and lows. Our Summers do get warm and dry, the cesspool, I mean Portland will often get mid to high 90’s, and some triple digit temperatures in July and August, we tend to run 5-10*cooler here on the lower slopes of Mt Hood. For us upper 80’s and mid 90’s are typical, we will see an occasional triple digit day or two. September usually starts warm and dry and begins cooling mid month, with a bit more rain as the month progresses, this week the forecast is for rain M-F So for us, Late June-mid September is when our wood seasons, if kept covered the rest of the year, it will lose a little moisture, but not too much, our humidity levels don’t leave much for the air to absorb, once the weather turns. Fortunately, the Conifers that are predominate in our area, will release their moisture rather quickly, but they will also reabsorb moisture if exposed to the weather, just the wood and weather that we have to deal with. Doug
Same only because I have a heavy canopy of tree cover, most all of my racks hardly get any sun (maybe an hour or two late in the day) so I am purely relying on air flow to get them dry. When it rains or is humid, things tend to stay a lot more wet and moist on my property so keeping things dry as possible is a must. If I had an open field with brilliant sunshine many hours a day, I could see leaving it un covered for a bit and let that cycle take place, with of course there being a fine line.
I think what Dennis is saying is correct. And here’s my theory as to why. I’m no scientist but part of Dennis’s philosophy of three year seasoned firewood hinges on living cut trees, split stacked and covered. As most of us have learned in that scenario it produces some great firewood. The extra long drying time is associated (IMO) with the wood being full of actual sap from the living tree. It takes much longer to dry sap as opposed to evaporate water. And sap in any tree consists of sugars. And sugar even to my unscientific mind is a fuel. Hence repeated wetting of the wood will wash some of that sugar out reducing the amount of stored fuel in the wood. Hope that’s clear as mud
Funny enough I knew that but just the other day my poor ol mom had to find out the hard way. With ChatGPT or whatever it’s called. She’s 90 and been reading her mother’s journals, she was a prolific writer of the days events, every day. Anyway there was one mention of my grandfather delivering wood to “The brickyard” back in 1948. She’s obsessed with finding out where this brickyard is. Internet doesn’t know of course, local historical society has no clue. I can’t think of any large brick buildings going up in that time frame where they may have fired bricks right on the spot. All our big brick factories were built well before that. Historical Society mentioned Kensington Ct as a large brick producer back then. Im trying to explain to mom there’s no way gramps would have driven twice a day to Kensington in his old hay truck that had no brakes before there were highways LOL Anyway she visited my eldest sister who is a big fan of ChatGPT and she made the same query of it I already searched for. And sure enough if you push it to answer long enough it will start making stuff up. Found reference to Brickyard Rd in our town. Right in the middle of a swamp where no road has ever existed. Follow the sources it claims it used to find this road and find out they are maps in the library of Congress that are not available on the internet,,,,,,so how did AI find them? Also they are Insurance fire maps that only were done in tight industrial zones for insurance companies. They state they never would have made a map of any outer regions of a town. IE it just made it up. I think there’s veracity to what Timberdog says but I also believe you can get a better product by covering right away. Now if I would only take my own advice,,,,
