Best firewood for a wood burner

The short answer

The best firewood is dry, seasoned hardwood with a moisture content below 20%. It burns hotter and longer, gives more heat, makes less smoke and leaves less soot and creosote in the chimney.

What matters most is not the type of tree but how dry the wood is. Dry softwood burns better than wet hardwood.

The 20% moisture rule

Freshly cut wood is full of water. When you burn it, much of the fire’s energy goes into boiling that water off instead of heating your room. The fire burns cooler and smokier, and that smoke condenses in the chimney as creosote, the tar-like deposit that causes chimney fires.

Seasoned wood, dried until its moisture content is below 20%, burns cleanly and hot.

How to check

• Use a moisture meter. They are simple and widely available. Split a log and press the pins into the fresh inside face, not the outside, which is always drier.
• Look and listen. Dry logs are lighter, often have cracks at the ends, and make a sharp knock when tapped together. Wet logs feel heavy and make a dull thud. These signs help, but the meter is the reliable test.
• Watch the fire. Wet wood hisses, steams, smokes heavily and is hard to keep going.

If you are buying firewood, ask whether it is seasoned or kiln-dried and check a few logs yourself before you buy a large load.

Finding firewood in Malta

Malta and Gozo have very few trees grown for fuel, so most firewood sold here is imported and comes from a small number of suppliers, usually in nets, bags or bulk crates. A few things are worth knowing:

• Kiln-dried logs have been dried in a kiln rather than left to season outdoors, so they usually arrive below 20% moisture and are ready to burn. They are a good choice for Maltese homes, where outdoor seasoning is slow in the damp winter.
• Bulk crates work out better value for regular burners, but you need a dry, airy place to store them.
• Offcut crates of mixed hardwood and softwood are fine for kindling and short fires, as long as the offcuts are untreated timber, not chipboard or painted wood.
• Wood briquettes made of compressed sawdust are another option for stoves. Check that your stove manual allows them, and use them as the maker recommends, because they can burn very hot.
• Local wood from pruned olive, carob or other trees can be excellent once fully seasoned, but freshly cut wood needs a long time to dry.

Whatever you buy, keep it dry once you have it.

Why wet wood is a bigger problem in Malta

Maltese winters are mild, but they are damp. Firewood stored outside, in a garage or against a damp wall can pick up moisture again, even if it was dry when it arrived. And because many Maltese homes only light the fire on colder evenings, the chimney is often cold when the fire starts, which makes smoky, wet-wood fires even more likely to leave deposits.

Wet wood is one of the main reasons for the problems people call a sweep about: smoke coming into the room, blackened stove glass and a strong tar smell.

Hardwood or softwood?

• Hardwoods, such as olive, carob, oak and other dense woods, burn slowly and steadily and give long-lasting heat. They take longer to season.
• Softwoods, such as pine, light easily and burn fast and hot. They are useful as kindling and for getting the fire going, but burn through quickly and, if not fully dry, can leave more resin in the chimney.

A good approach is to start the fire with dry softwood kindling to get the stove and flue warm, then add hardwood logs once the fire is established.

What never to burn

• Wet or unseasoned wood.
• Painted, varnished, stained or treated timber, including old furniture, doors and window frames.
• Pallets you are not sure about. See the section on pallet wood below.
• Chipboard, MDF and plywood, which contain glues.
• Driftwood, which is full of salt.
• Household rubbish, plastics, cardboard and glossy paper.

These give off harmful fumes, damage the stove and leave corrosive or sticky deposits in the flue. Take them to a WasteServ civic amenity site or dispose of them properly instead.

What about pallet wood?

Because firewood is hard to find in Malta, many people chop up old pallets from factories and warehouses. Some pallets are safe to burn in small amounts, but many are not, and you cannot tell by looking at the wood alone.

Check the stamp

Pallets used for international shipping carry a stamp with a wheat-ear logo and a treatment code:

• HT means heat treated. The wood has been heated to kill pests, with no chemicals. Plain, clean HT pallets are the only kind worth considering.
• MB means methyl bromide, a toxic pesticide fumigant. Older pallets and pallets shipped from abroad can still carry it. Never burn MB pallets.
• No stamp means you cannot know how the wood was treated. Leave it.

Pallets never to burn

• Painted or coloured pallets, such as blue, red or brown hire pallets. The paint gives off harmful fumes.
• Pallets with chipboard or compressed-wood blocks, which contain glues.
• Pallets that have carried chemicals, oils, paints or food that has spilled and soaked in.
• Pallets that are wet, mouldy or rotten.

If you do burn clean HT pallets

• Use them as kindling, in small amounts, not as your main fuel. Pallet wood is usually softwood that burns very fast and hot, which can overheat a stove and leaves more deposits in the flue if it is not fully dry.
• Remove nails and staples where you can, and sieve them out of the ash, so they do not end up in the bin or the garden.
• Check it is dry. Pallets stored outside can be soaked through.
• Have the chimney swept more often if you burn a lot of softwood or pallet wood.

If in doubt, leave it out. A stove burning the wrong thing can cost far more in damage and cleaning than a net of proper firewood.

Log size

Split logs dry faster and burn better than whole rounds. Follow your stove manual for the maximum log length that fits the firebox comfortably, leaving space around the logs for air to circulate. Do not overfill the stove.

How to store firewood in Malta

Good storage keeps dry wood dry through the winter:

• Off the ground. Stack logs on a pallet or rack, not directly on the soil or a damp floor.
• Covered on top, open at the sides. Rain needs to stay off, but air needs to move through the stack.
• Away from walls. Leave a gap between the stack and the wall so air can circulate.
• Sunny and breezy if possible. In summer, a sunny, airy spot helps wood season faster.
• Bring a day or two’s supply indoors before burning, so it is at room temperature and fully dry.

Avoid storing large amounts of firewood in damp garages or basements, and never stack wood right next to the stove or fireplace.

Keep the chimney clean

Even with the best firewood, every fire leaves some soot and creosote. Have the chimney swept at least once a year before the first fire, and again mid-season if you burn most evenings. Our guides on how often to sweep a chimney and what creosote is explain why.

If your stove still smokes or blackens its glass quickly even with dry wood, the chimney may be dirty or partly blocked. See our guide on why a fireplace smokes into the room.

Still deciding what to install? See open fireplace, wood burner or pellet stove for how they compare on fuel, storage and cleaning.

Book a sweep

clear.mt arranges chimney and wood burner cleaning across Malta and Gozo. Book early, because sweeps are busiest from October to January.