Firewood: the most important rule? It must be DRY!
When we buy a car, we know perfectly well that fuel matters. We may have the best engine in the world, but if we power it with poor-quality fuel, we cannot expect it to perform at its best.
The exact same principle applies to a wood-burning stove or fireplace.
We may have a modern, efficient appliance, perfectly installed and connected to a professionally built flue, but one thing remains fundamental:
we need to provide it with good fuel.
And in the case of firewood, even before discussing whether beech, oak, acacia, ash, or fir is better, there is one characteristic that matters more than all the others:
FIREWOOD MUST BE DRY.
This is the real golden rule.
How dry should firewood be?
Here it is important to clarify a concept that often causes confusion.
Wood naturally contains water, and it is not necessary to reach 0% moisture (which, under normal environmental conditions, would in any case be unrealistic)
To be considered suitable for combustion, firewood should have moisture below 15%. The closer we can get to 10%, for example, the easier it will be to achieve quick ignition and lively combustion. The EPA also indicates a moisture content below 15% as a benchmark for good combustion.
Why is this so important? For one very simple reason:
water does not burn.
When we put wet firewood in the firebox, some of the energy produced by the fire is used to heat and evaporate the water contained in the wood instead of producing useful heat.
The result?
Wet firewood generally means:
- greater difficulty lighting the fire;
- lower combustion temperature;
- more smoke;
- glass that tends to get dirty more quickly;
- more deposits in the firebox and flue system;
- less useful heat;
- less efficient and more polluting combustion.
The Veneto Region, in its guidelines on biomass use, recommends wood with a moisture content below 15%, explaining that excess moisture reduces the heating value and makes it more difficult to reach high temperatures in the combustion chamber.
In other words: before blaming the stove, fireplace, or flue, let’s check the firewood!
So, what is the best firewood to burn?
Here we can have some fun going into a little more detail.
Different species have different characteristics, especially when we compare them at the same volume.
Denser woods, such as beech, oak, black locust/acacia, and ash, generally contain more energy in the same volume than lighter woods. At the same weight and moisture content, however, the energy differences between the various species become much less significant than is often thought.
In practice, we can distinguish them, simplifying:
Beech
One of the great classics of firewood. Good heat output, beautiful combustion, a good flame and good embers. It is a very versatile and pleasant wood to use.
Oak
Hard, dense woods, excellent for maintaining the fire and producing long-lasting embers. They are particularly useful when we want a longer combustion.
Black locust, commonly called acacia
It is a very dense and tough wood. Once combustion is well established, it is particularly useful for maintaining heat and embers for a long time.
Ash
Another excellent firewood, with good heat output and even combustion.
Birch
It lights easily and produces a beautiful flame. It can also be very appealing in fireplaces where the visual aspect of the fire is important.
Fir and other conifers
They are lighter woods and tend to burn quickly, producing a lively flame. Precisely because of this characteristic, they can be very useful, especially during the lighting phase, provided, of course, that they are thoroughly dry and used in accordance with the appliance manufacturer's instructions.
But be careful not to turn all this into an extremely complicated science.
There is no need to drive yourself crazy!
Sometimes it almost seems that lighting a wood-burning stove requires a degree in forestry.
“That one is no good because it is too light.”
“That one is fine, but only after three years.”
“That one produces too much flame.”
“That one produces too many embers.”
“That one is suitable only at 6:37 p.m. with a northeast wind…”
Calm down!
The characteristics of different wood types exist and are useful to know, but in real life a good wood-burning stove or fireplace can work perfectly well with many different types of wood.
If we have beech available, good.
If we have oak, good.
If we have ash, good.
If we have acacia, good.
If we have a mixture of wood types, excellent.
The essential thing is that it is untreated wood, suitable for combustion and, above all, DRY.
Between firewood considered “premium” but damp and more common wood that is perfectly dry, there is no doubt for us:
we choose dry wood.
A little trick for a good fire-lighting
If we want to further improve combustion, we can use different types and sizes of wood at different stages.
When lighting the fire, we want to achieve a beautiful flame and a high temperature quickly.
The aim is not merely to light the logs.
We need to heat the firebox quickly and, above all, the flue: by increasing the temperature of the smoke, we encourage the activation of the natural draft.
For this reason, it is very useful to start with dry firewood split into small pieces, together with a suitable firelighter.
We can use, for example, thin beech pieces or light, very dry woods such as fir, provided they are compatible with the manufacturer's instructions.
Once the fire is well established, the firebox is hot, and the flue has started drafting properly, we can move on to larger logs and denser woods.
For example, acacia/black locust, oak, or other hardwoods can help us achieve a longer burn and longer-lasting embers.
The EPA also recommends starting with a small, hot fire using dry kindling, gradually adding larger pieces and leaving enough space for air to pass through.
It is a very simple principle:
small and lively for starting, larger and longer-lasting once the fire is going.
How can I tell whether my firewood is truly dry?
The best method is very simple: measure it.
Small wood moisture meters are available at relatively low cost and provide a very useful reading within a few seconds.
A tip: to obtain a meaningful measurement, split a log and measure the moisture on the freshly exposed inner surface, not simply on the outside of the piece.
The outside may in fact appear perfectly dry while the heart of the log still contains a great deal of water.
As a reference, let us reiterate:
below 20% = minimum level for combustion
around 10–15% = dry wood and generally excellent for use
There is no need to chase 0%.
You simply need well-seasoned, dry firewood.
Buy the firewood or prepare it ourselves?
Both solutions work perfectly well.
We can buy firewood from a trusted supplier, asking for wood that is already seasoned and ready to use.
Alternatively, we can buy or prepare fresher wood and let it season ourselves.
In the latter case, however, you need to give it time and, above all, air.
The timing can vary greatly depending on the species, the size of the pieces, the climate, the exposure, and how the wood is stacked. As a general guideline, the EPA recommends at least about six months for softwoods and at least one year for many hardwoods; in other conditions, even more time may be needed.
So we should not rely solely on the calendar.
We measure the moisture content.
It is the simplest way to know what we are really putting in our stove.
And now we come to one of the most common mistakes: where should firewood be stored?
This is probably one of the most important points in the entire article.
Yet it is often underestimated.
SEASONING FIREWOOD SHOULD BE KEPT OUTDOORS.
It seems contradictory.
“But outside it absorbs moisture!”
“If it rains sideways, it gets wet!”
“Better put it all inside the garage!”
Not necessarily. In fact.
To season firewood properly, it mainly needs one thing:
AIR.
Water that may superficially reach the sides of the woodpile during occasional rain can dry out again fairly quickly.
Much worse is trapping moisture inside the stack and preventing air from circulating.
The EPA’s guidance is very clear: firewood should be stored outdoors, raised off the ground, and covered only on top, because closing the sides traps moisture.
The Veneto Region also recommends storing firewood intended for seasoning in a place open on at least three sides.
How to stack firewood correctly
So the ideal solution is a very simple one:
OUTDOORS + RAISED OFF THE GROUND + COVERED ABOVE + OPEN ON THE SIDES.
A shelter is perfect.
But a properly made top covering, a panel, or a tarp placed only on top, leaving the sides open, may be sufficient.
The purpose of the top covering is to prevent large amounts of water from continuously penetrating deep into the stack.
We must not turn the pallet into a waterproof gift package!
No tarp wrapped completely around the firewood.
No sealed stack.
No fresh firewood enclosed in an unventilated room.
Air must be able to enter from one side, pass through the stack, and exit from the other.
It is precisely this continuous air exchange that allows the moisture present inside the wood to escape gradually.
A stack completely wrapped in a tarp may seem very well protected, but it risks becoming a real moisture trap.
And at that point, instead of seasoning properly, the firewood can develop mold and, in the worst cases, begin to deteriorate.
So let’s remember just one thing
We can talk for hours about beech, oak, ash, birch, fir, and acacia.
We can compare heat output, density, ember duration, and flame beauty.
We can study the ideal size of the pieces and perfect the lighting technique.
All of this information is useful.
But if tomorrow you were to remember just one thing from this article, we would want it to be this:
THE BEST FIREWOOD IS DRY FIREWOOD.
Good dry firewood makes lighting easier, helps the firebox quickly reach the correct temperature, produces less smoke, creates less dirt, and allows our stove or fireplace to work much better.
Buy it dry from someone you trust, or prepare it yourself.
But if you need to season it, give it time and give it air.
Keep it outdoors, raised off the ground, protect it mainly from above, and let the sides breathe.
Because we can have the most beautiful fireplace in the world, the best stove, and a perfect chimney…
but in the end, a fire can burn well only the fuel we give it.
And with firewood, the golden rule always remains the same:
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