Which Firewood Should I Buy?

Firewood falls into two broad categories: hardwood and softwood. In this article we'll look at the different hardwood species that are commonly available as kiln-dried logs for domestic heating.

Whether you’ve been burning for years, or buying your first crate, it’s important to know which wood best suits your preferences.

Firewood isn't all the same - the burning characteristics differ depending on the species of tree it comes from.  For example, the grain structure of the wood has an impact on the energy density and ease of lighting. Some species grow faster than others; some produce denser logs; all have their own distinct aromatic qualities.

You might just buy whatever firewood is available. But if you have a choice, or aren't sure, it's worth knowing the difference.

What types of firewood can I buy in the UK?

In the UK there are a handful of hardwood species that are widely available both from online and local retailers. These include Ash, Oak, Beech, Birch, Alder and Hornbeam. Some UK suppliers import kiln-dried logs from across Europe; others process wood sourced from local plantations.

Below we compare these different types of firewood across the properties that matter to a stove owner: ease of lighting, burn time, energy density and cost.

Which wood has the highest heat output?

Heat output typically correlates with the density - lighter wood has more air gaps which don’t provide any calorific value.

All six species produce good heat when they are dried or seasoned properly. While energy density differs across species, you should focus more on the other characteristics when making your choice. Burn time and energy density correlate quite closely - hornbeam and oak will burn for longer than birch and alder.

The trade-off from burn time is the ease of lighting. Anyone who has tried birch or alder will understand how easy they are to light.

This chart highlights the relationship between ease of lighting and burn-time. Cost also loosely follows the same trend, with the more expensive logs having a longer burn time.

This is the exact reason hardwood mix options are available to buy - it’s easy to start a fire with birch or alder and then fuel-up with denser, longer-lasting species such as Oak or Ash.

Different firewood species have different qualities

The burning characteristics are not the only things to consider. Some people care about the aromatic qualities of specific species, the sustainability, or even the appearance of the logs.

The distinctive white Birch bark and how that can look stacked in your log basket might mean more to you than pure burn-time metrics. Or you might prefer the distinctive aromatic qualities of Beech or Alder.

Sustainability of firewood species

It goes without saying - in order to burn firewood, the trees must first grow, then be cut down. Lots of firewood is sourced from managed forest plantations, while other firewood can come from more natural sources. In the UK, a lot of kiln-dried wood is imported and therefore for the end consumer it's difficult to see where the logs have come from without investigating the supply chain.

The growth characteristics and environmental issues affecting different species can give a rough indicator of the sustainability of a specific firewood. As a rough guide, the denser species like oak and beech are slower growing than the lighter birch and alder. There are other considerations too, Ash dieback has decimated the UK Ash population, which puts more pressure overall on using the species for firewood.

So how do I choose which firewood to buy?

Knowing the trade-offs between species allows you to make an informed decision on which firewood best suits your burning habits. If you want the best of both worlds: a hardwood mix that contains a combination of easier to light woods like birch and alder - plus a species like oak or hornbeam for longer fires and less maintenance (once your fire is hot!).

However you might opt for a good all-rounder like Ash or Beech, which can be split up into good kindling and provide longer lasting fires than birch or alder.

Whatever you decide, you can always try something different next time!

Firewood species at-a-glance

In summary

• All UK hardwoods burn well when dry, the species choice matters less than the moisture content.
• Denser woods (Oak, Hornbeam) burn longer but are harder to light.
• Lighter woods (Birch, Alder) light easily but don't last very long.
• All-rounders (Ash, Beech) provide a good compromise between length of burn and ease of lighting.
• Hardwood mixes are available to provide the best of both worlds.

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