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Can You Use Lava Rocks in a Wood-Burning Fire Pit?

Can You Use Lava Rocks in a Wood-Burning Fire Pit?

Fire pits are great, especially during the cold seasons. It provides your body with the warmth it needs during the period. You can as well use a fire pit for cooking. Hence their importance cannot go unnoticed. However, there are different types of keeping the blaze in the fire pit, like wood, cedar oak, and many more.

Because fire is involved, this only means that fire pits pose some risks depending on how you handle it and what you use to keep the blaze in the fire pit. Do you use materials that can cause harm to you and your family, or do you make sure that you stay safe at all times?

In this article, we will explore the usage of lava rocks in a wood-burning fire pit and see whether it is a good choice or a wrong choice to go with.

Is it Safe to Use Lava Rocks in a Wood-Burning Fire Pit?

When it comes to protecting wood-burning fire pits, lava rocks are an excellent choice. They form a partially permeable barrier that is ideal for shielding the pit from the elements.

It also improves the evenness of heat distribution. Uneven heating is terrible for fire pits because it can cause cracks in the surface. Your pit will be shielded from developing excessively hot spots if you use a thick layer of lava rocks under the firewood.

If your fire pit uses gas burners, lava rocks will also protect them. The lava rocks block the surface flame and protect the burner from overheating, which could cause it to warp or break.

Advantages of Using Lava Rocks For Wood Burning Fire Pit

It has a porous protective surface

A porous surface means that there are empty spaces along the rock’s surface that allow gasses or liquid to flow through it. These open spaces, known as vesicles, are caused by air pockets within the lava flow.

The porous surface allows water to drain, keeping your lava rocks dry and safeguarding the bottom of your fire pit from surface heat.

It ensures that the flame is distributed evenly

Because of their exceptional ability to retain heat, lava rocks used in a propane fire pit provide warmth throughout the burner pan.

It protects the burner from direct sunlight

A range 3 inch to 4-inch layer of lava rock can protect the burner from different weather conditions. It also protects the burner from the surface flame due to its natural insulating properties. As a result, the fire pit will last longer and perform better.

It is resistant to heat

Lava rocks’ heat resistance adds shelter to your gas fire pit.

It is resistant to water

In this regard, lava rock is somewhat contradictory. Moisture adheres to the rock’s large surface area, giving it a high water holding capacity. Despite its strength, it also has excellent drainage.

Dangers of Using Lava Rocks For Wood Burning Fire Pit

When heated, lava rock that has been in a fire pit can burst and explode if it is not completely dry. It is best to keep your fire pit regularly covered to avoid this. These hand-crafted metal covers are ideal for keeping your lava rock or other fire pit materials dry when not in use.

Though they are costly, they will save you a lot of money by extending the life of your fire pit materials. If you cannot cover your fire pit, it is best to let any wet lava rocks cool completely before lighting your fire pit.

Pro Tip: In connection to covering your fire pit regularly, you should also check the drain holes to ensure they aren’t blocked and are draining water properly. Water accumulation along the bottom of the burner pan prevents lava rocks from drying, posing a risk.

What Do You Put on the Bottom of a Wood-Burning Fire Pit?

After considering the various advantages of placing a fire pit with lava rocks, you realize that this is the best option for maintaining this backyard looking beautiful and functioning safely. Rather than simply filling the bottom of the fire pit with concrete, you can choose to cover it with a thick layer of gray, black, or brown lava rocks.

This will make the fire pit appear cleaner and more organized. It will also ensure even heat distribution within the pit. Choosing this particular filler allows you to gather safely around the heat source on cold nights.

Safety Measures When Using Lava Rocks in a Wood-Burning Fire pit

Ensure you buy high-quality lava rocks

Before using lava rocks, make sure you get genuine lava rocks rather than synthetic ones since synthetic lava rocks explode in flames like fireworks.

Because they resemble each other, it is easy to confuse a synthetic rock for a natural one. As a result, be highly careful when selecting them, and remember to check the tag and pose questions when buying.

Maintain the Dryness of Your Lava Rocks

Keep your lava rocks moist-free at all times to avoid explosions if they get wet. It doesn’t mean a disaster-level blast, but rather violent cracks that can be frightening.

You can keep the lava rocks from getting wet by taking them out and storing them in a dry place after use or by concealing the fire pit with water-proof materials when not being used. Even if you have considered every necessary precaution, water can still get into your fire pit.

This is the reason you should keep the drain hole of your fire pit clear at all times to avoid moisture absorption of the lava rocks. To avoid being injured, stand a safe distance from the fire pit until the explosions stop.

Burn the wood one piece at a time

When burning wood on lava stone, always remember how much the fire pit can hold and how much the lava stone can protect. Let the wood burn down entirely on its own every time.

You may have seen people use water to put out a fire when they need to turn the fire pit off, but this is not recommended. Although it may serve its purpose, there is a chance that the lava rock will absorb the water and explode. Water can also cause damage to fire pits, particularly those made of metal or clay.

In addition, if you burn the lava in a concrete fire pit, the fire pit may crack due to constant heating and cooling. These cracks can detract from the appearance of the fire pit and, in the long run, can interfere with the strength of the concrete, which is dangerous. To avoid these cracks, only burn wood in small amounts. The pieces should be thinly cut so that they can burn quickly.

How Should You Use Lava Rocks For a Wood-Burning Fire Pit?

The first step is to build a fire pit in a well-ventilated area. Verify the requirements for building a backyard fire pit in your city’s specific ordinance before you start any work. To understand more, contact your local fire department.

Place the pit in a location where it can drain quickly so that the bowl does not become swamped with water. Another benefit of using lava rocks as a fire pit lining is that they are highly durable. The material’s porous nature means that it cannot retain water.

Add several inches of lava rock to the pit or bowl. The rocks should be about 5 inches from the lip of the pit. Once the protective layer has been laid down, you can place the burning wood on top.

Do not use anything other than lava rocks when building a structure. These materials may explode if heated to high temperatures. If you don’t have lava rocks on hand, look for lava glass beads with the same properties.

Keep in mind that even when heated, lava rocks can erupt if moisture is present. There will be a rapid expansion of water in the pores, which will cause the rocks to break. The fire pit must be constructed with an efficient drainage system to prevent flooding.

However, after rain, be extra cautious when lighting a fire. If possible, wait to light a fire until the rocks are completely dry before doing so.

Be aware that your fire pit may still develop small cracks due to repeated cooling and heating, even if a layer of lava rock is present to protect it. You won’t have to worry about your fire pit breaking if it’s built to code.

Use firewood that is not too large to reduce the risk of hairline cracks forming. If necessary, cut up the large pieces of hot wood. The concrete surface of the pit will crack if it receives too much heat from large pieces of firewood.

You can easily clean your lava rocks if they’ve become discolored or discolored too much. In a bucket, pour water over the rocks and let them soak for a few minutes. Adding a tiny amount of mild liquid soap to the water is also an option. This mixture should be allowed to sit for a few minutes before use.

Using a liquid to flush out the lava rock pores will remove any dust or debris that may have accumulated. Lay the rocks out on a flat surface after they have been cleaned. Before putting the rocks back in the fire pit, let them dry out.


We have discovered that lava rocks are very effective in a fire pit, and it is highly recommended. However, some precautions come in handy to ensure that you are safe and don’t pose any risk to you and your surroundings.

As we have learned, lava rocks tend to explode if placed in a fire pit when damp; such precautions should come in handy to ensure your usage of lava rock is safe all the time.