Here is a guide for folks buying firewood locally that derives from years of my experience cutting, splitting, and burning wood to heat my home. I have no commercial interest in firewood as I neither buy nor sell it, but my experience can assist buyers to assure they are getting quality firewood.
First of all, there is some confusion about the size of a cord. When wood is sold in a unit other than a full complete cord, it hampers your ability to “shop around” for the best price, since you have no way of knowing how much wood you’re getting from each seller. A cord is a tight stack of wood with the dimensions 4’x4’x8’. So, if the logs are cut 16" on average, that's three stacks that are 4' by 8'. If the logs are only 12", then it takes FOUR stacks that are 4' by 8'. I doubt many sellers of a cord of firewood in 12" logs will deliver FOUR stacks that are 4 feet high by 8 feet long. Most likely, it will be two, maybe three such stacks. This is liable to happen if you never see the wood stacked before you buy it, such as if they come and leave a pile from a pickup truck. So make sure you see the wood stacked. Divide 48" by the average length of the logs to determine how many 4’x8’ stacks you should get. Two (2) is the answer only if the logs are a full 2-feet long. And those probably won’t fit into your stove/fireplace.
(It was recently pointed out to me that local customs and laws may influence how wood is sold and what a cord colloquially means. In this guide, cord is used in the traditional sense as described above. Regardless of what the local practices are, you should be familiar with them and the traditional standards so that you can get a relative sense of value of a given unit of wood.)
A word about pick-up trucks. One pickup truck load is NEVER a cord, unless it's a 1-ton with a dump bed or a full size truck with extensions on the bed rails. A seasoned cord of white oak weighs over 2 tons, and you can’t carry that in a regular old pick-up truck. (An unseasoned cord of white oak weighs even more, and has greater volume too.) A midsize truck (like a Dodge Dakota) stacked tight and high is about 1/3 of a cord. A full-size truck with an 8’ bed (½, ¾, or 1-ton with a regular bed and no extensions on the rails to allow for higher stacking) if stacked tight and high is about ½ of a cord. Of course, you can fit less in the truck if it’s randomly tossed in as a pile rather than tightly stacked in the truck. Again, you can’t know how much is there for sure until you see it stacked 4’x8’ and measure the average length of a log to determine how many stacks you should get.
Even if the metric for measuring wood and comparing quantity/volume is the cord, all wood is not created equally in terms of heat content. As an example, a cord of seasoned white oak produces ~ 26 million BTUs per cord when burned. Red maple has only about 18 million BTUs/cord. So if you buy a cord of red maple instead of a cord of white oak, you're getting only 70% as much heat from that cord. What is a good hardwood for furniture or cabinets is not necessarily a good wood to burn for heat content. Wood sellers frequently boast that they are selling you cherry (20 million BTUs/cord) or walnut (20.2 million BTUs/cord). You’d be far better off with hedge apple (aka, osage orange - 33 million BTUs), black locust (27 million BTUs), hickory (26.7 million BTUs), or mulberry (25.8 million BTUs. (Admittedly, cherry, maple and some others smell pleasant when burned, and that has some value.) A full list of seasoned wood heat contents can be found with a simple google search.
(If you're burning the wood in a fireplace for purely aesthetic reasons rather than to heat you home, the heat content of the various types of wood may not be of concern to you. On average, the efficiency of an open fireplace is close to zero, meaning that its net contribution to heat in your home is negligible. So the heat output of the wood isn't that important in an open fireplace (although log burn times may be and these are proportional to heat content, e.g., an oak log will burn longer than a similar maple one.) In this case, you may want a wood like maple or cherry, both of which, when properly seasoned, light easily, do not emit many sparks (locust is terrible for sparking, and so is unseasoned wood), and have a pleasant smell when burned.)
There is also confusion relating to the idea of "seasoned" firewood. Part of the confusion is that the term “seasoning” seems to imply that the wood undergoes some compositional or chemical change after the tree dies, like a wine that’s aged. It does not. It just loses water (or rots eventually especially if not split). Firewood should simply be dry in order to produce the most heat. If it's wet or green, much of the heat will be consumed boiling off the water content of the firewood, and that heat literally goes up the chimney, not into your house. There is no magic here: burning wet or green wood is like having a wet towel in the fire. Moreover, if you burn wet or green wood you're going to wind up with CREOSOTE. I won't go into it, but CREOSOTE build-up puts you at risk of a chimney fire or house fire. You can burn that wet green wood for years and get away with it, but you're destroying your chimney and risking your home. Then there are these folks who say, "I'm burning such and such [wet, unseasoned, unsplit, poor-quality] wood, and it heats my home just fine.” Well sure it does. You don't realize the creosote unless you look for it and even if you do it takes years to build up because it's a slow process. And that guy also doesn't realize that if he burned dry seasoned wood, instead of requiring 6 cords for the winter, he would only need 4 cords, since the a large part of the heat doesn't go to boiling off the water. So the proper question is not whether wet green wood will burn, of course it will! The question is whether a cord of wet and/or green wood will produce as much heat as a cord of dry wood, and it won’t, so it's not worth as much. So if seller A and seller B both charge $150 a cord, but Seller A’s wood is wet/unseasoned and Seller B’s is dry/seasoned, Seller B’s is a better deal by 25% or so. It’s like you’re getting 25% more wood/heat!
Here is the underlying logic of seasoned firewood. When you heat with wood, you are basically using stored solar energy. The tree takes sunlight and converts it to chemical energy in the form of wood. Great. Awesome renewable energy source that's good for the environment because you can grow more trees but you can't make more coal or natural gas. So bravo if you're burning wood. But, as stated above, much of that energy will got to boil off the water content of the wood if it's not dry. In comes solar energy again. After the tree is cut, if you split the logs, the sun will begin to dry the wood. If it is not split, it will not properly dry/season, because the bark holds the water in. So good is bark at keeping the water in (that’s its job), some woods will rot if not split – birch for example, and often cherry. So seasoning begins when the wood is split, not when the tree dies. (I admit that if the tree is down and bucked but not split that it will season quicker when split, but it’s not like it doesn’t need ANY seasoning and you should burn it right after splitting.) If you split the wood and stack it in the sun for ~6-12+ months, the sun dries out the wood, so when you burn it, your house gets more heat. So there are 2 parts of the solar-energy-in-the-form-of-wood-heat: 1.) the tree growing; and 2.) the wood drying in the sun for 6-12 months, depending on the ambient heat and humidity of your locale, how you store it (covered? room for air to circulate around the ends? in the sun or shade?), and the type of wood. (Denser and water laden woods take longer to season/dry out - e.g., pin oak, which takes well over 12-18 months to season because of high density and water content.)
But most of the wood you buy is NOT properly and fully seasoned. Why not? 2 reasons: 1.) people are not like squirrels. They have all summer to split firewood, but they don't. They wait till heating season, then they go cut the wood - because they know you will probably not notice the difference and can never know with certainty just how long the wood has been split; and 2.) because it takes a lot of space and some extra time and effort to cut and split and stack the wood and leave it there for a year before you sell it. You can imagine. In fact, the way you can get around this mess is to buy next year’s wood this year, and let it season at your place – then you’ll know how long it’s seasoned for sure. What did you say? You don’t want to spend $800 on 5 cords of wood this year that you won’t use till next year? And you don’t have room to store it? Now you see why these guys sell you unseasoned wood. Just like you, they don’t want inventory, they want cash. And they don’t have room to store all of it either. So they store it in the forest - uncut, unsplit, unseasoned - as standing trees.
Here are some ways to tell if your wood is NOT properly/fully seasoned WHILE you’re burning it:
• the smoke coming from the chimney is BLUE. Dry/seasoned wood burns with white or light grey smoke.
• you have trouble with smokey wood, filling up the house with blue smoke, and your fires are hard to start and get burning
• the wood smolders and hisses, and crackles and pops and bubbles of liquid come out the ends when it's burning. (That's the water boiling out.)
• you have glass door(s) on your fireplace or woodburner and black goo (creosote) builds up on the doors, requiring frequent cleaning. If the wood is properly dried and seasoned, your glass door(s) will remain clean, or will have just a thin white dust like powdered sugar on it.
Here are some ways of telling if the wood IS properly seasoned BEFORE you burn it, when you’re inspecting it, hopefully prior to paying for it.
• there will be lots of cracks/fissures on the ends of the wood. The more and the wider the better - see photos below
• the bark will begin to separate from the wood, and will peel off easily or will be gone already
• the ends of the wood will be gray and weathered, not bright and new like freshly cut wood – the wood will look old.
• When you bang together two pieces, it will have a high-pitched hollow sound, just like bowling pins colliding (bowling pins are kiln dried!). Not a dull, lower pitched thud sound. Be aware that even green wood, if it is frozen solid, will make the bowling pin sound, so if it’s frozen, this test won’t work.
• The wood will NOT be super heavy. Properly seasoned firewood feels relatively light, even hardwoods like oak. That wood they sell pre-packaged in shrink wrap at the local supermarket for $5+ a bundle that says it's seasoned – it is NOT seasoned. You know that for a fact because the plastic wrapper has condensation on the inside. So that wood is full of water. When you pick it up, you can tell because it is SUPER heavy. If you want to feel what properly seasoned wood feels like, take one of those heavy wet/green logs (and weigh it if you like) and then leave it beside the woodstove or register for a month or two and then pick it up and feel the difference (and weigh it again to determine how much water weight it lost).
What basically happens it that wood sellers have found that raising prices leads to decreased sales, so they have found other ways to cut corners and make more money. This includes trimming down a full cord to a “truckload,” and not incurring storage, handling, and transportation costs associated with proper seasoning of the wood. And because most people don’t know how to evaluate quality or quantity of the wood, only price, they have gotten away with it. The problem is that you can’t possibly compare the value of the wood unless it’s all a relatively uniform product. To do that, you must insist that the wood be a full cord, properly and fully seasoned, and be a good hardwood like white oak that produces 25 million BTUs or more heat per cord.
I hope that this helps. A truly seasoned cord of good hardwood firewood is indeed worth ~$150+. Good luck finding some. It’s out there. But Caveat Emptor. And remember: trust, but verify.
Here are some photos of firewood in varying stages of seasoning. If nothing else, note the progressive darkening of the ends of the wood as they become progressively more "seasoned" or basically dry and weathered.
First is white ash, cut and split from a standing tree the week this photo was taken. Note that it is bright white, looks fresh, has no fissures or bark separation, no sign of darkening/weathering of the ends (other than some staining from a recent rain).
Here is the same wood, 12 months later. Note how much the ends have darkened! Note also the shrinkage of the wood as it has dried out! Wood will shrink 15-20% as it dries. (one of the logs has shifted positions in the stack.) If the image were larger, you would also see some good fissuring and the beginning of bark separation.
Next is totally unseasoned oak, cut and split about 3 months before the photo was taken. There are no fissures in the wood, the color of the ends is not darkened or weathered at all, and the bark is tightly adherent to the sap wood with no signs of separation. This wood is totally unseasoned, but typical of what might be advertised as "seasoned" firewood.
Here is the same oak, over 1 year since the previous photo and about 16 months since cut and split. (Photo taken from a different area of the stack; variation in end color is due to the wood being restacked this past summer - one side of the original stack got more direct sunlight than the other and therefore led to more darkening/sunbleaching of the ends).
Next is big leaf maple that was cut and split about 5 months before the photo was taken. Note that the ends are beginning to darken/weather, but it is showing very little early fissuring and the bark is still tight to the sap wood, so it is still not fully seasoned.
Next is honey locust. It was down and bucked into logs for about a year and then hand split about 4 months before the photo was taken. It is fully and deeply fissured, and there is no bark left on it - it fell off entirely with handling of the wood. This wood is seasoned, but barely, because most of the time it was down it was not split, so the water couldn't get out of of the center of the logs. The increased surface area after splitting will help with that. I did not burn this wood until 14 months after splitting, 10 months after this photo was taken.
Next is pin oak that was seasoned for 18+ months at the time of the photo. Note the deep fissures, significant weathering/darkening of the ends, and bark separation. This stuff is ready to burn and if it's not, too bad, because it's not going to get much drier! Note that pin oak takes a very long time to season because of its high density and water content. As the fissures slowly develop and the bark slowly separates on a wood like this, it slowly loses its water content.
Here is a piece of the honey locust pictured above after it was left by the woodstove (in very low humidity) for 2 days. This is ideally dried and seasoned wood, a textbook picture if you will. In fact, the wood in the stack did not dry out this much or show this degree of "ideal" checking/fissuring even after 14 months of post-splitting seasoning. The outdoor humidity in Central Ohio is too high for the wood to dry out this well - but the more your wood looks like the "textbook" piece below, the better off you are! (Of course, if you have the luxury of space by your woodstove, you can markedly accelerate and enhance the drying/seasoning of your wood by stacking it by your stove for a few days or weeks before you burn it, effectively kiln drying the wood.)
To better illustrate checking and the ability of the wood stove to kiln-dry a piece of wood, here is a piece of red oak that was cut and split well over 18 months ago that was stored outside covered from rain by a piece of plastic:
While you can clearly see the checking/fissuring of the wood, it is not obvious from afar, even though this wood is clearly and thoroughly seasoned, beyond what is generally considered necessary. In the next photo, look how the checking opens up on the other end of the wood after just 3 hours beside the woodstove. (Both ends would open up like this if I would rotate the wood or leave it there for a few days.) I have noted increases of 100-150 degrees in flue gas temperature effected simply by letting the wood dry beside the stove like this for a few days or weeks: