Is Oak a Good Firewood

Is Oak a Good Firewood?

Latest posts by Mike Lillyman (see all)

Oak has the reputation of being excellent firewood, perhaps the best Firewood. So, what makes a superb Firewood? Here we will go through the qualities that make Oak stand out as my most preferred Firewood.

About ten percent of the Oak species in the world are present in the USA. They are divided into two categories, Red and White Oaks.

White Oak scores higher than Red in terms of heat produced but comes second when the ease of splitting is considered. When I started harvesting Firewood, I had the romantic image of wielding a maul and watching the oak logs split neatly.

Now I use a mechanical splitter because while Oak is an excellent heat source, it can be challenging to split. But splitting is one of many properties that affect the choice of Firewood, so let’s go through the various qualities that make Oak stand out as your Firewood of choice.

For me, and I’m sure for most people, the amount of heat the Firewood produces is the critical factor in choosing a Firewood. But let’s first have a brief look at the various oak species and their characteristics before we answer the question “Is Oak a Good Firewood?”.

Red Oaks

  • Shumard Oak– hard and dense but the large pores make it burn quickly.
  • Black Oak– less porous than Shumard and seasoned correctly, a great firewood.
  • Willow Oak-a very hard Red Oak but prone to a little crackling in the fire.
  • Pin Oak– is even harder than Willow Oak. Widespread and competitively priced.
  • Cherry Bark Oak– is probably the best of the group producing a clean long-lasting fire.

White Oak

  • Oregon White Oak– produces a high amount of heat but tends to have a lot of messy ash.
  • Post Oak– is a great firewood for stoves but the smoke may be an issue in open fires.
  • Bur Oak– is at the top of heat produces, long burning but the large pores can create crackle.
  • Chestnut Oak– has the advantage of quicker seasoning and won’t crackle as much as Bur oak.
  • Swamp White Oak-one of the hardest of all the Oaks, long burning with high heat production.

The BTU Rating

I am always intrigued about why such a convoluted method, the British Thermal Unit, became the accepted measure of heat, but that’s the way it is. What is important is the score that individual Firewoods get in terms of heat produced. Let’s look quickly at the relative BTU scores for the three oak species:

  • White Oak BTU per Cord: 29.1 million
  • Red Oak BTU per Cord: 24.6 million
  • Bur Oak BTU per Cord: 26.2 million

So, from the comparative scores, White Oak produces the most heat of the three species. Utah State University created a table of the more common Firewoods and their BTU scores.

The table shows that the Oak varieties are among the top heat producers, with fruit trees like Apple at 27 million BTU and Osage Orange topping the scale at almost 33 million BTU.

In terms of heat produced, all three Oak varieties do exceptionally well. But, to be excellent, the Firewood also must burn slowly. Typically, hardwoods burn slower than softwoods, and Oak is a hard and dense wood. So how does Oak shape up in the duration stakes?

Burn Rates

Oak Firewood

It turns out that Oak is one of the slowest woods to burn because of its density. So, along with Maple, Ash, Hickory, and Cherry, these hardwoods are considered great Firewoods because of their slow burn rates.

The rate of burn is greatly affected by the amount of air present around the Fire. Many fireplaces have ratings detailing the heat output settings and the burn duration times. They are typically identified as HHV and LHV values.

The HHV figure refers to heat output, while the HHV figure indicates the burn duration. While these figures show the Fireplace’s capacity, the Firewood’s condition will significantly impact the heat produced. So how does Seasoning affect your Fire?

The Importance of Seasoning

If you want a clean-burning, good heat-producing fire, Firewood should not have a moisture content exceeding twenty percent. This is because the density of Oak makes it such tremendous slow-burning firewood and also a slow-seasoning wood.

Many years ago, hard lessons taught me the benefits of giving Firewood a generous seasoning time. There is a wide range of figures quoted to guide you as to the required seasoning time, but there are so many additional factors that impact the seasoning time that the quoted range is of little use.

My experience has always been that the Seasoning will take longer than expected. P{lan for that.

Aspen, for example, will need about six months to season. Oak will reach the twenty percent moisture content level in twelve to twenty-four months. Does that make Aspen a better choice? No. Not when the relative heat per cord is compared. Oak will produce fifty percent more heat per cord.

You can make the seasoning process more efficient by correct stacking methods and the dreaded splitting.

Splitting is vital in allowing the Oak logs to reach the required moisture content because it dramatically increases the surface area open to the atmosphere. In addition, the surface areas that splitting exposes are non-bark-covered surfaces which are far more efficient at allowing moisture to leave the log.

Stacking

Stacked White Oak

By careful stacking, the seasoning speed of Oak Firewood can be accelerated. So, ensure that your stacking is done correctly with the logs stacked off the ground, and the stack is orientated to allow the wind and sun to do their work.

Ash and Silver Maple will beat Oak to the twenty percent moisture content mark, but Oak will still trump them in terms of heat produced.

How to Tell When Your Oak Firewood is Ready for the Fire

The easiest way to measure the moisture content is with a moisture meter. With experience, simply lifting a log will tell you a lot about the moisture content, but moisture meters are cheap and helpful, so I would suggest getting one. Moisture meters are divided into two categories: those with pins and the more expensive pinless ones.

I’ve used a Stihl moisture meter with pins for a good couple of years and it has never let me down. It will cost you under thirty dollars and the display is big and clear. Another moisture meter in the same price bracket is the Tavool Pin Type moisture meter which has a range of readings from six to sixty percent. It is powered by two AAA batteries and is a great and reliable tool.

If you don’t like the idea of pins and you want to measure the moisture content of valuable furniture as well as firewood then the Tanscos Pinless moisture meter may be what you need. It will cost you around forty dollars.

Oak has a lovely way of showing you how much it has seasoned by turning a light grey color. In addition, cracks at the end of the logs will also appear to give you some indication of the seasoning process.

Tapping to logs together will also indicate the moisture content. Dry logs have an excellent sharp sound; wet logs will produce a dull thud.

One additional benefit of a moisture meter is that you can identify sections of your stack that are drying quicker or slower than the whole stack. This is an excellent guide to indicating which area of the stack you should be sourcing your Firewood.

Time for the Fire

Fireplace

All the hard work has been done. The logs are seasoned, and it’s time for the fire. So what parameters are there to sort the good firewoods from ones you should rather avoid?

Smoke

Logs that produce a significant amount of smoke are not what you need in your Fireplace. While an outdoor fire is not quite as fussy, you certainly don’t want your living room filling up with smoke. Not only is smoke unhealthy, but you also run the risk of choking up your chimney with creosote which can be a serious fire risk.

Firewoods are categorized rather vaguely when it comes to smoke production. They are either low or medium, and I can’t say I’ve ever seen a Firewood rated as high smoke production. We are, of course, only talking about seasoned Firewood here.

Softwoods fall into the medium smoke generation category, while hardwoods typically are in the low smoke section.

All three Oak species generate a low amount of smoke, as do Osage Orange, Hickory, and Maple.

Fragrance

And now we move into the realm of ‘nice to haves.’ Each morning when I open the doors to my woodworking shop, the different fragrances of the raw timber put a smile on my face.

Similarly, the rich fragrance of a wood fire using cherry or apple logs is enticing, and, in this regard, Oak only rates as ‘good’ against the excellence of the fruit trees. Now I would concede that fragrance is a personal preference. Still, Firewoods are rated as ‘Excellent, Good, and Poor on the Fragrance meter, and to complicate things a little, the ratings do change along with individual selection.

So, what matters most is what you like; typically, the smell of an oak log burning in the Fireplace has a pleasant fragrance to most people and me.

Sparks

Sparks are a little less optional. Sparks are dangerous in an open fireplace, and using Firewood with a high resin content will result in some active spark action. Some species to avoid in this area are essentially the softwood conifer-type ones like Pine, Poplar, and Spruce.

Oak is rated as having few sparks, and I have never been bothered by an oak fire sending out dangerous sparks. The fruit tree species like Apple and Cherry also fit comfortably in the low spark section. However, Mulberry does not, and care should be taken when burning Mulberry logs.

Coals

The benefit of a particular firewood species producing good coals relates to the Fire’s longevity. Good coals mean the Fire can be revitalized the following day, particularly in wood stoves. The density of Oak makes it one of the top species to produce coals of a long-lasting nature.

Joining Oak in the Gold Circle of good coal-producing species are, amongst others, Maple, Beech, and Black Locust.

Availability

Red and White Oak are some of the most common trees in the USA and are ideal for Firewood. However, if you are going to harvest Firewood yourself, easy access is a prime concern, so plan your harvesting carefully to make it sustainable for the years ahead.

Just a quick note of caution. Be careful not to transport Firewood from distant areas. There is a real danger of introducing alien species and insect infestation to your area, and you may run into legal problems doing so in several places.

FAQs

Question: What do the HHV and LHV Stamps in my Fireplace Mean?

Answer: This should be a simple measure. Light a piece of wood and time how long it burns. Would that it was so simple. Usually, there will be two numbers stamped on your Fireplace: The Listed Max BTU (HHV) and the listed Burn Time (LHV)

They tell you how much heat can be produced in a certain amount of time. Much like a car providing details of miles per gallon consumption efficiency rates, the higher the speed, the lower the fuel efficiency.

So, you may see a rating such as HHV 50 000 BTU s and duration of 3 hours compared to the LHV figure of 20 00 BTU s and 8 hours. The two are inversely proportional. The higher the heat output, the shorter the duration.

Question: What can Firewood Ash be Used For?

Answer: The ash from your Fireplace is an excellent additive to your garden. It will repel insects from sensitive plants if you sprinkle ash around the plant.

Wood ash mixed with a bit of water makes an excellent mild abrasive to clean glass and metal objects.
Ash is super absorbent, so use it to soak up any driveway spills, and if you need a little additional traction on your driveway, ash comes in handy to provide some grip.

Suppose you have an outside fire pit store the ash in a drum so that you can spread the ash over the embers when you want to put the Fire out. Ash is a great fire extinguisher.

Question: What is the Best Size for Oak Firewood Logs?

Answer: A lot will depend on the size of your Fireplace but aim to have a range of logs from three to six inches wide. The ideal length of the Firewood log is around fourteen to sixteen inches. Use the smaller logs to start the Fire; once there is a good flame, the larger logs can be added.

Conclusion: Is Oak a Good Firewood?

There are many excellent kinds of wood to burn in a fire but Oak, and it doesn’t matter which one of the three you choose, will give you a fire that will be comfortable, warm, and long-lasting. The added seasoning time is a small price for Firewood that is dense and long-burning and up there with the best in terms of heat generation.

My first choice is always Oak, and if you are fortunate to live in an area where Oak is plentiful, I suggest you try it. It is such an honest wood that delivers great heat over a long time with minimum fuss. I can’t think of a better Firewood.

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