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Firewood

Image of piling firewood.On this page: Save money – get your firewood early, stay warm – burn dry firewood, questions to ask when you buy firewood, tips for drying firewood, checking if the firewood’s dry, what not to burn, Get the most heat from your firewood (PDF flyer)

Get the most heat from your firewood

Not all firewood is equal – dry wood gives more heat and less smoke. Find out how to get maximum heat from the wood you burn.

Save money – get your firewood early

If you buy or collect your own firewood, it pays to get it early. Firewood is generally cheaper in spring or summer, and getting it early gives you more time to stack and dry it before use.  

Image of home fire.Stay warm – burn dry firewood

Dry wood gives you more heat, quicker than wet wood. Wet wood needs a lot of energy to heat up and evaporate the water it contains before it burns properly and heats your home. As the water vaporizes, the heat goes up the chimney, not into your home.

Dry wood, compared to wet wood, is cleaner to burn, causing less smoke and air pollution and fewer associated health problems. Smoke contains harmful particles, not visible to the human eye and small enough to get into human lungs and cause health problems. In winter, most of these harmful particles come from wood burned in homes, not from industry or vehicles.

Image of firewood.Some questions to ask when you buy firewood

Please note that these questions cover the wood’s quality, not the quantity.

How dry is the wood? How long has it been cut and stacked for drying?

Some sellers may be able to tell you the moisture content of the wood (if they have a moisture content meter). Wet or unseasoned wood is cheaper to buy, but you need to have the space to store it for up to a year or more, until it’s dry enough to burn. Some firewood suppliers sell pre-dried wood. It might cost more, but the extra heat it provides could outweigh the extra cost.

What type of wood is it – hardwood or softwood?

Hardwood costs more, gives off more heat but takes longer to dry than softwood.
Softwood is cheaper, gives off less heat but dries more quickly than hardwood.

Is the wood split?

Wood will dry faster if pre-split.

Tips for drying firewood

Even if your firewood is dry, storing it well will keep it that way. Here’s how:

  • Split large bits of wood into pieces no more than 10-15cm thick.
  • Remove bark, or stack the wood with the bark at the bottom, so the moisture can evaporate. Bark slows down the drying process.
  • Stack the wood in a covered, well-ventilated area with a roof or tarpaulin.
  • The length of time for it to dry depends on the type of wood and how wet it is. Softwoods, like pine and macrocarpa, normally take 6-12 months. Hardwoods like gum can take up to 18 months.

Checking if the firewood’s dry

Dry firewood:

  • has cracks in the ends
  • weighs less than wet wood.

Some ways to test if wood is dry enough to burn well are to:

  • bang two pieces together - dry wood should make a loud, hollow crack
  • tap the wood with a key or coin - dry wood should make a sharp, resonant sound
  • put a small piece of wood on glowing embers in your woodburner. The top and sides should catch fire in less than a minute.

Signs that your firewood is not dry enough:

  • The wood is hard to light and hisses and sizzles.
  • The fire produces more smoke than heat.

What not to burn

Besides wet wood, there are other materials that are dangerous to burn in your home fire. When the materials listed below are burnt, they can give off toxic substances. They can harm your and other’s health, the environment as well as your fireplace, woodburner or chimney.

Material

Toxic substance/s it can
give off if burnt include…

Potential effects these toxic substances can have include…

human health

the environment

your fireplace, woodburner or chimney

Treated wood
  • arsenic (from CCA treated wood)
  • tin (from LOSP treated wood)
  • boron

Short-term exposure:

  • sore throat
  • lung irritation

Long-term exposure:

  • lung damage
  • liver and kidney damage
  • damage to the central nervous system
  • increased risk of cancer

Ash will be contaminated (with arsenic, and may have high levels of copper, chromium, boron or tin). Shouldn't be put on the garden.

-

Painted wood

Depends on type and colour of paint but can give off:

  • lead
  • cadmium
  • barium
  • zinc
  • copper
  • tin

As above.

Ash is likely to be contaminated with one or more heavy metals.

-

Plywood
Particleboard
MDF
  • formaldehyde

Short-term exposure:

  • coughing
  • headaches
  • eye and skin irritation
  • asthma attacks

Long-term exposure:

  • cancer (suspected)

-

  • creosote in chimney - possible increased risk of chimney fires
Driftwood
  • dioxins
  • furans

Long-term exposure:

  • cancer (suspected)
  • problems with immune, developmental and reproductive systems
Dioxins can settle on plants, which, if eaten by livestock, contaminate milk and meat.
  • corrosion of woodburner’s metallic parts (due to high salt content)

Rubbish

  • plastics
  • disposable nappies
  • magazines
  • wrappers
  • boxes
  • VOCs (volatile organic compounds)
  • semi-volatile organic compounds (e.g. phenol)
  • chlorobenzenes, polyaromatic hydrocarbons, carbonyls (e.g. acetaldehyde, acetone and formaldehyde)
  • dioxins
  • furans
As above. As above. As above.

For more information on the effects of these toxic substances, visit the Agency for Toxic Substances and Disease Registry website.

Get the most heat from your firewood (PDF flyer)

View and print off a PDF flyer that contains most of the information on this page:

Get the most heat from your firewood (277 kb)