The majority of people with a wood burning or multi-fuel stove use seasoned logs on their stove. But this isn’t the most efficient fuel to burn.
Earlier this year, we asked 237 stove owners* what type of fuel they use on their wood burning or multi-fuel stove. The most common types were:
- seasoned logs (69%)
- kiln-dried logs (14%)
- free wood, grown in their own garden or collected from the local area or neighbours (13%).
Read on to find out which type is the best to use on a stove, as well as the costs of each one.
If you’re thinking of getting a stove or have recently moved into a home with one, visit our comprehensive guide to multi-fuel stoves and log burners.
The best wood to burn on a stove
You should ideally only burn wood with 20% or less moisture content. This is because:
- It’s more efficient. Energy won’t be wasted having to burn off the water first, so the heat output will be higher.
- Fewer potentially harmful particulates/air pollution are released into the air than when burning wet wood.
- It will minimise sooty deposits building up in your chimney, which can be a fire hazard.
Seasoned logs – ones that you have partially dried out or that have been dried out by the manufacturer – contain around 25% to 40% moisture. Because of this, they have a heat output of around 3kWh per kg.
Kiln-dried logs, which are dried out in a kiln before being sold, contain less than 20% moisture. Burning this type of logs produces a heat output of around 4.5kWh per kg.
Free wood that has been collected could have as much as 90% moisture in it. The heat output could therefore be just 1kWh per kg.
Briquettes – fuel created from crushing recycled wood or paper – have a low moisture content. It can be as little as 10% or less, so they have a heat output of around 5kWh per kg. Only six of the 237 people we asked use this type of fuel.
Ready to burn
If you’re buying your wood, look out for the Ready to Burn logo. This new government-backed scheme means that only wood from reputable manufacturers can display the logo on logs that do contain less than 20% moisture.
Our advice on using a log burner or multi-fuel stove tells you more about the different types of fuel, using them efficiently, and the Ready to Burn logo. You can also see our videos on lighting a wood or coal fire and keeping it burning well.
The cost of fuel for a stove
As you might expect, the wood with a higher moisture content is cheaper. We looked at five online log suppliers to find out the average cost of each type of wood. We found that:
- Seasoned logs cost around £125 per cubic metre
- Kiln-dried logs cost around about £140 per cubic metre
- Briquettes are sold by the kg and usually cost around £242 for 1,000kg.
The log prices are for hardwoods, such as ash, beech, birch and oak. Hardwoods do cost a little more than softwoods (such as pine and fir), but take longer to burn, so you’ll use less.
All the sites we looked at deliver across the UK, and the prices for seasoned and kiln-dried logs don’t include delivery, but the price for the wood briquettes does.
The cheapest wood for your stove
Although seasoned wood has a high moisture content, and free wood has even more moisture, that’s not to say you can’t use it – just dry it out yourself first.
Depending on how wet the wood is, you may need to store it for up to two years for it to dry. You’ll need a designated area to store it, so that air can get to it but moisture can’t. You can buy a moisture meter to check when it’s ready. These cost as little as £10.
If you’re using wood that you’ve found (such as by the road or in a skip), make sure you have the right to take it and that it hasn’t been treated with any chemicals. You’ll also need somewhere to store it while it dries out.
If you have the room and can plan ahead, this could be a great way to save on wood.
Thinking of getting a stove? Our stove costs tool will help you find out whether a stove could save you money on your heating bills, or be an expensive luxury.
Why it might not be best to burn wood on a multi-fuel stove
Wood burning stoves are designed to only burn wood-based products – you can’t burn coal on them. Multi-fuel stoves can burn coal and wood.
But not all multi-fuel stoves burn wood as efficiently as a log burner would.This is because, to burn at its best, wood needs to sit on a bed of ash with air coming from above.
Coal, on the other hand, needs air to be able to circulate from below.
A lot of multi-fuel stoves have a grate for the coal to sit on. This is ideal for the coal, but not for the wood. 72% of the people we asked use wood on their multi-fuel stove instead of coal.
If you’re thinking of buying a stove and want the option of burning wood or coal, then look for a multi-fuel stove with a removable grate, so you can adjust how it burns the different types of fuel. If you’re likely to only ever burn wood, then a dedicated log burner would be a better choice.
Watch our stove buying video – go to buying a multi-fuel stove or log burner.
*August 2017 survey of 237 Which? members who have a stove as well as central heating.