A good fire can be spoilt before the match is struck. In any firewood moisture comparison, the difference between properly seasoned logs and damp wood is clear: dry logs light more readily, give out more usable heat and leave far less trouble in the stove and chimney. For homes across Norwich, Norfolk and North Suffolk, choosing the right fuel is one of the simplest ways to enjoy a safer, cleaner-burning appliance.
Why firewood moisture matters
Wood contains water naturally. Freshly felled timber can hold a surprisingly high amount of it, often well above 40% and sometimes much more. When that wood is put on a fire, much of the heat produced is spent boiling off the trapped water rather than warming the room.
That is why wet logs tend to hiss, steam and struggle to stay alight. They may produce plenty of visible smoke, but smoke is not the same as heat. A smoky, slow burn can leave more soot, tar and creosote deposits inside the flue. Over time, this increases the need for careful maintenance and can raise the risk of a chimney fire.
Dry wood burns hotter and more completely. It is easier to control, creates a clearer flame and usually leaves a lighter, finer ash. It also helps the glass on a stove stay cleaner, although any stove can still blacken if the air controls are shut down too far.
For most domestic wood burners and open fires, aim for logs with a moisture content of 20% or below. This is also the standard expected for small volumes of wood sold for immediate domestic use in England. Lower is not always automatically better if wood has been stored poorly or has become overly brittle, but between about 12% and 20% is a sensible working range for seasoned firewood.
Firewood moisture comparison: green, seasoned and kiln-dried
The labels used for firewood can be confusing, particularly when buying a load of logs for winter. The terms below help make a useful comparison.
Green or freshly cut wood
Green wood is timber that has been recently felled or split and has not had enough time to dry. Depending on species, when it was cut and how it has been stored, its moisture content may be anywhere from 35% to over 60%.
It is not suitable for burning straight away in a stove or open fire. It can be bought cheaply for future use, but it needs proper seasoning first. That means splitting it to a suitable log size, stacking it where air can move through it, keeping rain off the top and allowing time for moisture to escape.
A common mistake is assuming that wood is dry because it came from a dead tree or has been sitting in a pile for months. If it has sat on wet ground, been covered with an airtight sheet, or remained in large rounds, it may still contain far too much moisture to burn well.
Seasoned firewood
Seasoned firewood has been air-dried, usually over one or two summers. The exact time depends on the timber species, log size, local weather and storage. Ash has a reputation for drying relatively well, while denser woods such as oak can take longer to reach a good burning condition.
Properly seasoned logs can be excellent fuel, but the word ‘seasoned’ alone is not a guarantee. A log store in a sheltered Norfolk garden may dry wood well if it has open sides and good airflow. The same logs in a damp, enclosed shed may not. Check the moisture reading rather than relying entirely on a description from a supplier.
Seasoned wood is often the practical choice for households with space to store a supply in advance. It can offer good value, but only if it has genuinely reached 20% moisture content or less before it goes into the appliance.
Kiln-dried firewood
Kiln-dried logs are dried in controlled conditions and are commonly sold with a moisture content below 20%. They are usually ready to burn straight away and can be especially useful for customers without room to season their own wood.
The trade-off is cost. Kiln-dried logs are often more expensive than seasoned wood, but they can bring consistency, convenience and dependable performance. For a holiday let, for example, ready-to-burn logs are easier to manage than asking guests to judge whether a stack of wood is dry enough.
Kiln drying does not remove the need for sensible storage once the logs arrive. Wood left uncovered in the rain can absorb moisture again, particularly over a long wet spell. Keep it raised from the ground and protected from weather while allowing air around the sides.
How to test the moisture in your logs
A handheld moisture meter is the most reliable everyday tool for checking firewood. They are straightforward to use, but the method matters. Testing the weathered outside of a log can give a misleadingly low reading because the surface dries first.
Split a log and test the freshly exposed centre face. Press the meter pins firmly into the grain, then take readings from a few different logs in the load. If the readings are around 20% or lower, the wood should be suitable for burning. If several logs are above that level, give them more time to dry rather than mixing them into your ready-to-burn supply.
There are visual clues too. Dry logs are usually lighter than green wood, may show splits at the ends and make a sharper sound when knocked together. Their bark may loosen. These signs are helpful, but they cannot replace a moisture meter, particularly where the logs have been stored outside.
Do not be surprised if different species in the same pile give different results. A mixed hardwood load can dry unevenly, and a thick oak log may still be damp in the middle while smaller pieces of ash are ready to use.
What damp fuel does to your chimney and stove
Burning damp wood does not simply mean a less cosy evening. As smoke cools in the flue, its unburned particles can settle on internal surfaces. In a lined chimney or stove flue, that build-up may appear as black soot or sticky tar-like deposits. It restricts the route for combustion gases and may create strong odours when the appliance is next used.
Poor fuel can also make it difficult to get a stove up to operating temperature. Owners sometimes respond by leaving the door slightly open or repeatedly adjusting controls, neither of which is a good long-term solution. The answer is usually to start with dry kindling, use correctly sized dry logs and follow the appliance manufacturer’s instructions.
Regular chimney sweeping remains necessary even when you burn excellent fuel. Every appliance, flue configuration and pattern of use is different. However, dry wood supports cleaner operation and makes the sweep’s findings a better reflection of normal use rather than the effects of persistently wet logs.
If a chimney is producing excessive smoke, a stove glass is quickly blackening, or deposits are unusually heavy at sweeping, fuel quality is one of the first areas worth checking. Mr Chimney Sweep can provide practical guidance during a service, alongside clean, professional sweeping and an NACS Industry Standard Certificate of Chimney Sweeping.
Storing logs so they stay dry
The ideal log store has a roof, an open front or sides, and a base that keeps wood clear of soil and standing water. Airflow is more valuable than sealing the wood into an enclosed space. Stack logs loosely enough for air to circulate, with the split faces exposed where possible.
Avoid bringing a large amount of wood indoors weeks before you need it. A small basket or day’s supply near the stove is sensible, but a full indoor stack can introduce dust, insects and excess moisture into the room. Keep the main store outside, then bring logs in shortly before burning.
Covering a woodpile completely with plastic sheeting is another frequent problem. Rain may be kept out, but trapped condensation slows drying and can encourage mould. Cover the top only, leaving the sides open, or use a purpose-built store.
Choosing the right logs for your appliance
Hardwood generally burns longer and is popular for evening heating, while softwood catches fire quickly and can be useful as kindling or for getting a fire established. Neither category is automatically good or bad. The moisture level, log size and how you run the appliance matter more than a simple hardwood-versus-softwood label.
Use logs sized for your stove firebox. Overfilling the appliance reduces airflow and encourages a cooler, smokier burn. Two or three appropriately sized dry logs will normally perform better than packing in a large armful of questionable wood.
A moisture meter, a well-ventilated store and an annual sweep are modest measures that protect a much bigger investment in your home. On the next cold evening, let the flame tell the story: a bright, steady fire from dry wood is easier to enjoy and kinder to the chimney above it.