Oak trees are some of the most abundant tree species in the world. They are considered to be hardwood trees that belong to the genus Quercus. Oaks can be usually recognized through their acorns, as well as their spiraling leaves. There are more than 600 known species of Oak trees, but are Oak trees considered to be a good choice as firewood?
Let’s have a look!
Oak is considered to be exceptional firewood with an average output between 24.6 to 29.1 Million BTUs per cord. It contains very little sap and produces a clean, smokeless, and long-lasting fire. Furthermore, it produces fewer sparks compared to softwoods. As a downside, it can take a really long time for the oak to season properly.
What are the Different Varieties of Oak?
Oaks are usually categorized into two main categories when it comes to firewood, White Oaks, and Red Oaks.
White Oak varieties tend to mature rather quickly, their acorns only take up to a year to fully mature. Their leaves also have a more rounded shape and are lighter in color. Some of the most common White Oak species are Eastern White Oak, Chestnut Oak, Bur Oak, and Post Oak.
The other variety is known as Red Oak. The acorns here tend to take about 2 years to fully mature. The leaves have a slightly pointy end when compared to the white oaks. Some of the most common species within this variety include Northern Red Oak, Black Oak, Scarlet Oak, Water Oak, Willow Oak, and Pin Oak.
What are the Physical Characteristics of Oak?
Before we talk about the fire and heat characteristics of Oak, it is important to discuss some of the physical traits which play an important part.
Is Oak Easy to Split?
Oak trees are generally considered to be easy to split. This is one of the factors which makes Oak trees an excellent firewood option. When trees have a straight grain pattern, they are relatively easier to split, while trees that have a cross-grain are a bit harder.
Luckily with Oak trees, almost all of the species have a straight grain. You can use either an ax to split them manually or an automatic hydraulic splitter.
Red Oak species are a little easier to split while White Oak can be tougher. One great tip when it comes to splitting Oaks is to split them while they are frozen, they will be easier to come apart.
What Does Oak Smell Like?
Oak has a very distinctive smell; they have a mild earthy smell with some hints of citrus and vinegar. Some people consider Oak to be a good choice for smoking meat while some don’t like the vinegar-heavy smell.
How much Sap and Resin Content Does Oak Have?
One of the benefits of using Oak as firewood is its low sap and resin content. Almost every tree has some sap or resin content but with Oak, it’s really minimal.
Pine for example has a very high sap content which can stick to your clothes and equipment. High sap content is one of the reasons why Pine is not as good of a choice for firewood as Oak.
Moisture Levels of Oak
Oak, when compared to some other varieties like Pine, has a very low moisture content. This moisture content can be further lowered through proper seasoning. You can either leave the firewood outside to season or “bake” it in a kiln.
A low moisture level is essential and will lead to better firewood.
Heat Output and Efficiency of Oak
Oak is considered to be exceptional firewood. They have a very high heat output and efficiency.
On average, Oak delivers anywhere from 24.0 to 29.1 Million BTUs per Cord. On the other hand, Elm, Silver maple, and Aspen all have an average BTU output of below 20.
BTU stands for British Thermal Unit; this unit of measurement is most commonly used for evaluating the thermal output of timber. 1 BTU is the amount of energy it takes to heat 1 lb of water by 1 F. Similarly, a Cord of firewood equals about 128 cubic feet.
For perspective, 1 Million BTU is also equal to the energy generated by 179 gallons of oil and 7,283 kW of electricity.
Fire Characteristics of Oak
To determine the fire characteristics of firewood, factors such as Creosote build-up, the amount of smoke produced, and whether any coal is produced or not play the most important role.
Creosote Build-Up
Creosote is a by-product of burning wood, it looks like black tar and is considered to be highly flammable. Excess creosote buildup can clog your fireplace or chimney and is one of the leading factors behind chimney fires.
Trees that have a lot of sap, or if the firewood has not been properly seasoned, produce more creosote. This is why hardwood firewood is considered to be better, they have less sap and thus they burn cleaner.
Oak is known for producing very little creosote. This is due to its low sap content and hardwood nature.
Amount of Smoke
Oak is known to produce very little smoke (unless the firewood is wet, in which case any variety will produce much more smoke). Lower smoke production is a hallmark of great firewood.
Does it Produce Coals and Why It Is Important?
Whether firewood will produce coals and the quality of the coals are some of the biggest factors while determining the quality of firewood.
Good quality firewood will produce coals that can burn and provide heat for longer periods of time. These can be then used as overnight heat sources for wood stoves and re-igniting the fire in the morning.
Oak produces excellent quality coals. Larger firewood pieces can easily be used overnight. The dense hardwood Oak will easily outlast coals produced from trees such as Pine, Birch, and Aspen.
Should Oak Be Burnt in A Fireplace?
Oak is considered to be excellent firewood to be used in a fireplace. It has a high heat output which sustains itself for a long time. The firewood burns evenly and produces very little smoke and creosote. This factor will also prolong the life of your fireplace.
Furthermore, less no. of sparks also makes it safer to use both indoors and outdoors.
How Long to Season Oak Firewood?
Seasoning firewood is one of the most essential things you need to take care of. Unseasoned firewood will produce a lot of smoke as well as less heat. Firwood is considered seasoned when its moisture content is less than 20%.
Seasoning Oak can take a really long time. it is recommended to season oak for at least 1-2 years. The optimum seasoning time is 3-4 years. Splitting the firewood as soon as possible will lower the seasoning time.
This instrument can be used to measure the moisture content of your firewood. It’s simple and cheap.
Is Oak Firewood expensive?
There are over 80 species of oak in North America itself. You can find at least some kind of Oak trees present no matter where you live.
According to californiafirewoodsd.com in the state of California, a Cord of seasoned Oak costs 550$. Half a cord will set you back 300 bucks and 1/4 of a cord will cost you around 180 dollars.
Pros and Cons of Using Oak as Firewood
Oak is considered to be one of the best firewood out there, though like with everything it has its own pros and cons.
Pros:
- High energy output
- Common firewood
- Low sap content
- Great coal production
- Produces little smoke
Cons:
- Takes long time to season
- Can be hard to split in some cases
- The smell can be off-putting
How Does Oak Compare to Other Firewood?
Oak is considered to be top-notch firewood. Trees such as Black walnut, Pine, Birch, Sycamore, Black Cherry, Elm, Aspen all have a lower BTU output. Only Black Locust wood, Hickory, and Beech have comparable BTUs. Read more about Sycamore firewood here.
All of the latter firewood are great choices, but Oak is easier to find and cheaper to buy. On top of this, Oak also produces fewer sparks, although this does not impact the heat generated, it can be a safety hazard.
How to Tell The Difference Between Oak Varieties?
The easiest way to tell the difference between the two varieties is simply to take a look at the leaves. White Oak varieties have rounded tips whereas Red Oak varieties have pointed tips.
Frequently Asked Questions.
Does a water oak make good firewood?
Like all Oak species, water oak does make good firewood if seasoned properly. By burning characteristics it is virtually indistinguishable from other Red Oak varieties once seasoned.
Is pin oak good firewood?
Pin oak is another variety of oak that belongs to the Red Oak group. Similar to water oak, it is great firewood and it’s difficult to see the difference between the varieties.
When it comes to splitting pin oak, it is relatively difficult to split compared to other Red Oaks, especially once the wood has been seasoned. Furthermore, freshly cut pin oak does not smell pleasant, many people do not tolerate it.
Is willow oak good firewood?
When it comes to willow oak, it is not different from other red oak species as firewood. It has a similar density and makes good firewood for both indoor and outdoor use.
Is post oak good for firewood?
Post oak belongs to White Oak varieties and is slightly different from the Red Oak varieties listed above.
Though all oaks have very similar burning characteristics, White Oaks, including post oak, make slightly better firewood than Red Oak varieties due to higher density. In short, post oak is another excellent firewood choice.
How Much Wood Is in A Cord?
The definition of a cord in the United States is a volume of 128 cubic feet. But usually, it is measured as a stack of firewood which is 4 feet wide, 4 feet high, and 8 feet long.
Can I Only Use Seasoned Firewood for Burning?
Although you can use unseasoned firewood, the fire quality won’t be as good. There will be much more smoke and creosote created. Furthermore, the fire will not burn as hot and evenly.
How to Store Firewood?
Generally, you should only store firewood in a dry place, neatly stacked with one another. Do not store firewood next to wooden buildings or near your house for safety.
Conclusion
Oak is considered to be one of the best firewood out there. It has a BTU ranging from 24 to 29.1 million per cord depending on the variety. Oak firewood is known to have low sap content, great coal production, and smokeless fire.
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