• The Firewood Company

Why Does Firewood POP?

Wondering why some firewood you place in your fireplaces will crackle and pop? The Firewood Company investigates why some firewood sings with song and why others do not. PLUS: the best firewood for your outdoor entertainment areas.

If you have ever had the pleasure of owning a fireplace, the crackling sounds are almost memorising. However, some firewood can pop and crackle at a rate that they are not advised to be used in an open setting. Red hot embers on expensive rugs are a common problem with open fireplaces – the trick? It’s all in the wood you chose to burn.

Let’s understand why wood crackles …

Wood is not just a piece of dried trees – it’s made up of three major components, water, sap, and cellulose. When you place a piece of firewood onto a roaring fireplace the wood begins to get hotter and hotter. This increase in heat also warms the trapped water pockets and sap inside of the wood, the hotter it gets the more intense the crack. The sap and water eventually turn to a rolling boil as they begin to transform into gas or steam.

The cellulose also begins to heat. This substance is the main constituent of all plants – including trees, and your firewood. When cellulose heats it begins to break down and decompose – turning into a gas. Gas needs more space as it expands into the pocket trapped inside the wood. As the wood continues to get hotter and hotter, and the cellulose breaks down and decomposes, it allows the trapped gases to escape – causing a POP or CRACKLE. These gases escape either by an explosion or by finding their way through holes caused by insects.


What Wood Crackles More?

The more sap, or water trapped inside your wood, the more it will crackle. Some woods have a much higher sap rate than others. While wood that has not been correctly seasoned and is still wet will also cause larger pops in the fireplace.

This becomes very important if you have an open fireplace or outdoor fireplace. Not only for preventing home fires, but also to keep your family safe. If you have ever had the pleasure to enjoy a bomb fire, you will be aware that some of these pops are so big they can project large embers and even throw smaller pieces of hot wood in your direction. Particularly for extremely hot and large fires, throwing pieces of wet unseasoned wood or wood with a high sap content can cause issues. The gas heats so quickly that the wood can literally blow apart.


If you are planning an outdoor fire, ensure the wood is dry, not wet. This will allow for a successful light but will also protect your family from flying embers that can cause injury.

Woods that LOVE to Crackle and Pop

Softwoods typically have a much higher sap content than hardwoods. Douglas Fir is a wonderful little cracking firewood that also produces a great smell. However, it does pop and crackle so best to burnt in enclosed environments and not an open fireplace. Pine is also a popping delight. If you have unseasoned pine or softwoods, remember that they will spark and pop and can pose an issue. Macrocarpa is also a great burner known to pop and spark. As a hardwood, it will burn for longer and creates good heat. Perfect for closed wood burning systems.

If you are entertaining and considering lighting a fire, it’s important to do your research on your wood and ensure it's dry! Wet wood or green foliage will cause a pile of smoke and snap and pop dangerously. Turning your outdoor fun into a choking nightmare.

Happy Burning – need dry wood? The Firewood Company has you covered!

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