What does kiln dried wood mean?
Kiln drying is a process in which firewood is force dried in large chambers to reduce the moisture content much faster than if just air-drying fresh cut logs. In order to comply with the government’s new Ready to Burn legislation, and accreditation that is run by Woodsure, logs must be dried down to below 20% moisture content. It is now (as off Nov 2022) against the law in England (and soon to include Scotland and Wales) to sell firewood that does not meet these standards and carry the relevant accreditation by the supplier and shown on all packaging.
It is important to note that the term kiln dried logs does not guarantee the logs are dried to below 20% moisture content, but the ‘Ready to Burn’ logo should. The real test is to test the logs yourself using a moisture meter, but splitting the log down the middle to measure the internal reading.
What firewood dries the quickest?
- Ash has a lower moisture content than most species when harvested and dries quicker
- Less dense than oak or beech
- Has a characteristic white flesh colour and splits easily
- Great heat output
- Creates a steady bright flame
- Once cut and split into logs, ash can be air-dried within 6-12 months
What firewood burns the hottest?
Answer: OAK LOGS
British hardwoods like oak, ash and beech are always excellent firewood, but oak being very dense, would burn the longest. You can find all these species in our bulk bags, all sourced within a 100-mile radius of our base in Hereford.
What firewood smokes the least?
If the firewood is Ready to Burn approved and you're following stove manufacturers guidelines on how to light and maintain a fire, it should not smoke. So, if smoking, check your supply as it could be wet. However, the most well-known type of firewood that produces the least smoke is ash. Ash firewood is a great all-rounder, produces almost no smoke, puts out a great amount of heat and is quick to dry.
Why won't my firewood burn?
Three factors can play a part in an unsuccessful fire. Here is what you should look out for:
- Fuel: Ensure your firewood has a moisture content below 20% to ensure your logs have the best chance of catching. If your wood is wet or green/fresh, you will find it most challenging to get your fire going and keep burning.
- Dense Firewood: Some firewood is known to be denser than others. For example, oak can be slow to burn and will need aid from the kindling or smaller logs to get to a high temperature to start with.
- Airflow: If you do not have sufficient airflow in your wood burner, there is an high chance that your fire won't get going. Try opening the vents of your appliances to allow some airflow in.
Is firewood a renewable source?
Answer: Yes. As long as woodlands are managed sustainably, firewood is a renewable source of energy.
Firewood is generally considered a renewable source, as long as it is harvested responsibly. Trees used for firewood can be replaced through sustainable forestry practices, ensuring a continuous supply. When trees are selectively cut and new ones are planted, the carbon emissions released during burning can be offset as new trees absorb carbon dioxide. However, the sustainability of firewood depends on factors such as the availability of forests, proper management, and regional demand. Overharvesting or using firewood from unsustainable sources can deplete forests and have negative environmental consequences. Therefore, responsible sourcing and using firewood in conjunction with other renewable energy options are crucial for long-term sustainability.
What moisture content should my firewood have?
In line with new Ready to Burn legislation, wood sold in volumes of up to 2m3 will need to contain less than 20% moisture content. The scheme makes it easier for people to find the cleanest fuels for burning at home. If you purchase and burn firewood above this moisture level, you will not be complying with the new Air Quality Regulations of 2020.
We are often asked whether there is any real difference between kiln dried and seasoned logs. We have discussed this question in a blog blog here. Late summer is the best time to buy. Not only are you likely to get the driest wood from your supplier, having had the summer months to season, but it’s also much easier to make delivery and fill your store when it's drier and the days are longer. It’s much more pleasant to stack your logs away in the evening over a glass of wine or beer than flogging away in the dark evenings when it’s snowing or tipping with rain.
Seasoned vs Kiln dried
When is the best time to purchase firewood?
We are often asked whether there is any real difference between kiln dried and seasoned logs. We have discussed this question in a blog blog here.
Late summer is the best time to buy. Not only are you likely to get the driest wood from your supplier, having had the summer months to season, but it’s also much easier to make delivery and fill your store when it's drier and the days are longer. It’s much more pleasant to stack your logs away in the evening over a glass of wine or beer than flogging away in the dark evenings when it’s snowing or tipping with rain.
How do I know if my firewood is below 20%?
There are some ways of telling how dry the wood is, such as knocking 2 logs together and getting a nice hollow sound, rather than a dull thud, or observing how many cracks appear in the log end. Well cracked will usually suggest well dried. However, the best way to check the moisture content is by using a moisture meter. This will give you a pretty good guide to the actual reading of the firewood inside and out. Check inside by splitting a log open. Remember, however, moisture meters are not always 100% accurate, particularly the very cheap ones.
What's the most effective way to buy firewood?
Our large 1.6m3 bulk bag is the most cost-effective purchase, although you can also buy the 1.2m3 bulk bag or 0.8m3 bulk bag of kiln dried logs if you struggle to store a large bulk bag. If a bulk bag is difficult to unpack, you might want to opt for a pallet of small bags, choosing between 80 bags, 50 bags or 30 bags on a pallet. Some people find these easier to manage and handle. It’s down to personal preference as to which suits best. While all our little bags are fully recyclable, if re-use before recycle is your motto, a bulk bag might be your preferred choice as we offer a Return Your Bulk Bag Scheme which allows us to re-use bulk bags over and over.
When buying in bulk, you can purchase a large or small bulk bag of loose logs or, for the convenience of movement, little bags on a pallet of 50 or 80. The large bulk bag is the most cost-effective of all the products.
What firewood is best?
The aim of the below is to help you identify the most common types of firewood that you may have had delivered. It will help you better understand different species and how they each burn.
Oak Firewood: is very dense and takes a long time to dry, but it makes great firewood with a long burn and good heat output. At times, this wood will require a little more draft/air from the stove setting to maintain a good burn; however, once a good base is established, oak will burn hot and long.
Ash Firewood: Many people say this is the ‘king of firewoods’ and claim it can be burnt wet. Yes, it can dry quite quickly but still don’t burn it green. The fundamentals of firewood burn quality still apply, and the moisture content must be below 20%. Ash wood gives a nice bright flame and burns very nicely, slightly faster than oak.
Beech Firewood: Like oak, this is a very dense species and needs a lot of drying, but once dry, burns with a nice bright yellow flame for a long time. It also has smooth bark, so lovely to handle.
Alder Firewood: It can be quite a dense wood and characteristically has a distinctive orangey flesh colour. Once dry, it can be pretty light in weight and will therefore burn quite quickly. Alder is more commonly from Eastern Europe. It is improbable for you to be able to buy 100% alder sourced from the UK.
Birch Firewood: One of the most attractive logs due to its silvery, flakey bark. It Burns with a nice bright flame but will burn quite quickly. As with alder, any supply of 100% birch will almost certainly be from Eastern Europe and not British.
Ash Beech Oak Birch Alder
Is hardwood or softwood firewood better?
Many people say you should not burn softwood as it smokes, tends to spit, burns too quickly and can tar up the chimney. Once again, if you buy kiln dried logs or have the best way to season firewood in a dry and airy store and can dry to a moisture content below 25%, some of the above issues should be less of a problem.
Softwood (Spruce, Pine, Larch, Douglas Fir etc.) will have the same energy content per kilogram as hardwoods (Oak, Ash, Beech, Alder, Birch etc.), however being far less dense, you will need up to twice as many logs (or volume) to achieve the same heat output.
We only use British hardwood logs as we consider them to provide the best value for money.
Does kiln dried wood burn faster?
A common question and the answer is yes, but only if burnt on an open fire which has no air control. However, burning kiln dried logs on open fires is still recommended to avoid tarring up the chimney. Those that think mixing wet logs with kiln dried is good to slow the burn, then this is an entirely false economy as not only will you reduce the heat output, therefore needing more logs, but also you will tar the chimney.
In a wood-burning stove, kiln dried logs burn much more slowly and cleanly and provide a tremendous amount of heat – nothing can be more efficient. In a modern Ecodesign stove, the importance of logs below 20% becomes even more evident. Our MD Nic Snell has recently covered this topic here.
How to season firewood?
It takes a long time to season wood naturally – up to three years. Be careful when buying your logs, and make sure you get a complete understanding of the quality you are buying. Many suppliers will claim the wood has been ‘down’ for two years and therefore dry. That does not mean it’s dry. It is not about the time the tree has been cut down but about how the wood is stored. It must be sawn into log size, split and stored under cover for meaningful seasoning. The best thing to do is check the moisture on delivery with a moisture meter.
How long should wood be seasoned?
Length of seasoning is almost irrelevant, so be careful when being told how long wood has been ‘seasoned’. This is simply because if trees have been cut down and left in the forest without being split into logs, they will hardly dry. There is a reason why trees have bark – to stop the moisture from escaping. To season firewood logs properly and dry firewood quickly, wood needs to be cut and split into small logs to increase the surface area for drying and stored under cover with good airflow. Also, different species will dry at different speeds. For example, softwoods such as pine and spruce will provide dry firewood quickly, along with ash which is a quick-drying hardwood. Denser woods such as oak, beech and apple will take much longer to dry.
How much does your wood weigh?
You should never buy wood by weight as the wetter it is, the more it weighs. We only sell by volume, and you need to think in terms of a volume of energy. For example, a cubic metre of kiln dried wood is likely to produce twice as much heat as poorly seasoned wood. In this instance, the kiln dried wood would last you almost twice as long, therefore far better value for money.
How much firewood will I need for a typical winter?
A tricky question to answer as it will depend on so many factors:
- The efficiency of your stove
- The size of your property
- How well insulated your property is.
- How often you use the stove
- How cold it is
- How you use your stove – burning on full airflow all the time or on low heat.
However, this is a common question we get asked so to give you some idea. Assuming you are using the most efficient fuel – kiln dried, then in an average year you are likely to use 3-4 cubic metres of firewood. Remember that you will use significantly more wood if it is not dry because it provides far less heat energy – up to twice as much.