12/21/2022
Firewood Fundamentals #2: Moisture Content
We’ve all seen it…. Those pieces of wood that just refuse to burn. They sizzle, steam, smoke, but won’t burn. Why is that? It’s simple…. They’re just not properly seasoned.
So what is “seasoned” when we’re talking about firewood? It has nothing to do with anything pumpkin spiced, although that might be a neat idea…. Pumpkin Spiced Logs… it even has the PSL thing going for it… Hmmmm…. Ok I digress…
“Seasoned” in the historical common usage simply meant that cut and split wood had sat in a stack for a certain number of seasons and was therefore ready to burn. That’s still a pretty valid way to look at it, especially in a hot, dry climate like we have here in Oklahoma where wood dries predictably. Generally, if firewood is cut and split in the fall or winter it will be ready to burn after 3-4 seasons here. If it’s cut but left in rounds and not split, it could take up to 3 years to dry out enough to really burn. If left in full logs, it may take much longer. It may even rot before it’s ready to burn. Cutting AND splitting is absolutely crucial to producing good firewood.
So why does it take so long to properly season wood? And why is cutting and splitting so critical?
Well for one thing, there is a LOT of water in freshly cut wood. Pine and cedar may be 20-30% water. Oak, hickory, and pecan can be 30-40%. Cottonwood can be 50% or higher at times. Firewood of any species is not ready to burn until it falls below 20% moisture content. If you burn wood that isn’t properly seasoned, you could deal with excess creosote buildup in your chimney, which can be dangerous. Contrary to popular belief, burning hardwoods can cause creosote buildup just as badly as burning softwoods if it’s not properly seasoned. On the flip side, burning soft woods is not an issue if they’re properly seasoned. There are areas of the country who burn nothing except softwoods like pine and cedar, because that’s all that grows there. They have zero problems with it. If you use a modern catalytic wood stove, moisture is even more critical because wet wood will cause catalyst degradation issues and you may have to pay a lot of money to replace it.
Luckily, nowadays we can precisely measure exactly how much moisture content a piece of wood has. Moisture meters can be had on Amazon for $30-$50. If you burn a lot of wood you owe it to yourself to get one and check your wood before you take delivery of it. You need to split a piece of the wood you’re about to buy and take the measurement immediately on the freshly split face. The cedar I’m burning out back in the chiminea today is 8% moisture. Check the pic. It’s SUPER dry and makes great chiminea wood because it burns fast and gives me a big flame while throwing off a ton of heat. That’s exactly what I want. That’s actually a little drier than you want for general fireplace usage because it burns so doggone fast, but it’s great for a wood stove because you can damper it down and get a long burn with maximum heat release. Stay tuned for Firewood Fundamentals #3 where we talk about the amount of heat you get from firewood and why different kinds of wood are better or worse to use depending on what you’re doing with it.
Ok… on to our last point! Why is cutting and splitting so critical to getting wood to dry out enough to burn? It’s all because of surface area. The more surface area you can expose to the wind and the sun, the faster your wood will dry. You can count on around 2” of wood drying out to 20% moisture from a cut or split edge over the course of 3 seasons. If your wood is split to a maximum of 4” thick, there’s no piece of that wood that is more than 2” away from an edge and it’s nearly guaranteed to be ready to burn by the time it starts to get cold in the fall. So in general, you want your wood to be split reasonably small so it dries quickly. When we say reasonably small, we don’t mean into 1” pieces of kindling. But you don’t want big 8”thick, 8” wide pieces either. Not only do they take a long time to season, but they’re heavy, hard to handle, and don’t burn well even when they ARE seasoned. Why put yourself through that? It easier to handle that big single piece split into four 4” thick, 4” wide pieces. If you’re using it in a fireplace and want it to burn longer you can pack those pieces in tight, and if you’re using a wood stove it doesn’t matter anyway because you’re using the damper to control your heat and how fast the wood burns. Make it easy on yourself. The only place where you really see big wood being used is in outdoor wood boilers. Those things can handle 24-36” long pieces of whole logs. But I bet if you’re in central Oklahoma that you don’t have an outdoor wood boiler heating your house.
We here at Fallen Timber Firewood absolutely WILL NOT release a batch of wood for sale until it has been tested to be below 20% moisture. Unseasoned wood is a pet peeve of our founders. In most cases we test wood randomly as it’s being loaded into customer vehicles or onto our trucks or trailers for delivery. We’re serious about this. We also split wood to about a 3”x4” size. It dries fast, it’s easy to handle, and it burns great no matter if your application is fireplace, wood stove, camp fire, or cooking/smoking wood. Now…. We’re not Home Depot. We aren’t sawing this stuff exactly to size. Some will be a little smaller. Some will be a little bigger. But you will never see an 8” half round in your wood you get from us. You also won’t see any small 2-3” unsplit rounds. Those little things are sticks. We don’t sell sticks. You come to us for good wood and you deserve better than for us to sell you what got trimmed off Grandma Ethel’s oak tree and made it into a wood pile for sale.
