How To Arrange Lava Rocks On A Gas Fire Pit

Lava rocks are suitable for a gas fire pit as look great when burning, they disperse the flames, and spread the heat. Lava rocks can also withstand very high temperatures without cracking or exploding if you burn them from dry.

You’ll also find they keep the heat for several hours, making lava rocks for fire pit a great addition to carry heat through colder evenings and save on natural gas.

Lava rocks work as they disperse the flames and spreading the heat. Anyone can appreciate the warmth as much as how nice the fire pit looks.

Lava Rocks On A Gas Fire Pit

The heat from a burner goes upward yet adding a layer of lava rocks to your fire pit, the heat spreads around the burner.

Since the heat is radiated through the hot rocks, you’ll get a campfire to feel when you sit a safe distance around your fire pit.

In our guide, you can learn more about lava rock for gas fire pit, how best to place it, and other media you can use. By the end, you’ll know how much lava rock you need to distribute heat evenly around your fire pit. (Read How Far Does A Fire Pit Need To Be From A House)

Do You Cover Burner With Lava Rocks?

There is no need for a grate; cover the burner with rocks to endure high temperatures, making them excellent for gas fire pits. This keeps everyone warm and prevents hot and cold areas, which could later harm the fire pit’s construction.

Lava rocks create a drainage layer at the pit’s bottom and protect the gas burner from intense heat.

You may ask if these popular fire pit additions are fireproof, or you’ll need to change them?

Volcanic magma formed it, so fire pit lava rocks can withstand high heat, making them ideal for fire pits. Other rocks could splinter or explode when heated. While lava rock has excellent heat retention, lava rocks can save on gas use once they are up to temperature.

After the burner is lit, you can move the rocks back over the insulating boulders that protect the burner from the fire’s heat. There are a few things to consider before putting lava rock on your gas fire pits.

Because the rocks come from lava fields, they may be dusty as they arrive from your provider. They come in different sizes and are typically red or black.

Many people place an inch of pea gravel or sand on the fire pit’s bottom to form a base before adding the fire pit rocks.

Use smaller lava rocks for the first layer of fire pit media in your gas fire pit to a level a little below the burner. Small fire rocks act as an excellent base for your next layer of lava rock or fire glass.

How much fire pit rock you need depends on your fire pit’s shape and lava rock depth.

Here is more about fire pit media for gas fire pits.

You can layer ceramic logs on top of lava rock, and with the flames and the red glow, you can create the illusion you have a natural wood fire.

Lava rocks are inexpensive to use in a gas fire pit. Often called river rocks, you can use lava rocks easier while keeping your burner pan cleaner. (Learn What To Put Under A Fire Pit On Grass)

How to Start a Fire Pit With Lava Rocks:

It’s okay thinking you can use fire pit lava rocks, yet you need to know the best way to use them. Starting your fire pit with lava rocks is the first step.

Remove the rocks from around the fire pit’s burner if it has one. Open the gas valve slightly, then push and hold the ignition button. This will ignite the fire. Adjust the flame by rearranging the lava rocks around the burner.

In the absence of push-button ignition, use a long match. Remove the boulders and slightly open the gas valve. Light it with a match, then use the valve to control the flames. Move the pebbles to cover the burner safely.

Always wear safety gloves when using rocks for a fire or any of the following alternatives to using lava rocks.

Start a Fire Pit With Lava Rocks with Fire Glass

Fire Glass

Regular glass will explode in an outdoor fire pit if it gets too hot. These fire glass crystals have been tempered to be fire safe and heat resistant to withstand high temperatures. Beads of tempered glass don’t melt, burn, or fade. Fire glass is also smokeless and ashless, so ideal for use on gas fires.

Unlike lava rock, fire pit glass beads have smooth polished surfaces and sparkle to enhance your firepit’s fire.

Fire glass beads come smaller and more uniform, thus allowing them to transfer heat more evenly. In addition, fire glass generates a powerful heat source once heated and is an efficient heat conductor, like lava rock.

Fire pit glass comes in various colors and sizes, and the popular shape is a mound with a slight rise in the center.

Many individuals choose to layer fire glass on top of the lava rock in their fire pit. This is fine and cheaper than just lava rock.

When you are on a budget, you can get the best of both as lava rock and fire glass works well together for even heat distribution.

If you use fire glass on top of lava rock, arrange the fire glass thick enough that the lava rock is barely visible. Darker colored fire glass will better conceal the lava rock.

Fire glass lasts a long time but can lose some luster. Also, with the heat and use, you can find glass beads that might chip.

Fire glass beads can get dirty, so remove the glass beads, wash using dish soap, rinse and dry them and clean the burner pan of your fire pit while you have a chance.

Tumbled Lava Rock:

The jagged edges have been removed from this lava stone, making it more rounded and uniform than regular lava rock. If you choose, you can use it as a base or fill your fire pit with it rather than just as your base layer. It will keep the heat for a few hours afterward, as regular lava rocks and fire glass.


Sand can also fill a gas fire pit. It can be used with or without lava rock or fire glass. It won’t look as good, but it’s cheap and easy to install. It also distributes heat well. However, ash can get mixed in with the sand, causing a nuisance, especially if it gets wet.

No matter your fire pit media, gas burns in the same way as if you had fire pit rocks. Gas fills the pockets in between, which is then ignited toward the surface.

In either case, a protective layer must be placed between the burner and the flame to allow the gas to pass through.

Using a tiny size lava rock as a filler, such as 1/4 to 1/2 inch, is the easiest and most successful way to do this. This will slow down the rising of the gas a little, but not too much.

The goal is to bury the burner under this small lava rock until it is covered by at least 1/2 inch lava rock. (Please note that this is just for traditional style burners.)

Two of the most well-known burner manufacturers in the United States have slightly different opinions on the subject. One option is the 1/2′′ we described earlier. The other recommends filling only to the level of the burner’s top but not to the point of burying it.

Points of Caution

Check to see whether your fire glass or lava rock is interfering with the operation of a Spark Ignition Probe.

Some offer a protective cage, while others are just a probe, and you must make sure nothing gets in between the spark ignitors probes, preventing the spark.

Propane and natural gas are heavier than air, so it naturally flows down rather than upwards as it escapes from the burner. Check to determine if you have too much filler on the burner if the flame isn’t what you want. If this is the case, try eliminating some and seeing if the flame quality improves. (Learn What To Do With Ashes From Fireplace)

How Deep Should Lava Rock Be in Fire Pit?

Lava rocks are simple to care for and offer your fire pit a sleek, contemporary appearance. Fill your fire pit with a layer of lava rock that is 4-5 inches thick. Then, if the wood is your preferred fuel, stack it on top. If you’re using gas, you can add more lava rocks and fill the entire fire pit or cover the fire ring.

Fire Pit Safety

Fire Pit Safety and Fire Pit Tips

Ensure that your fire pit is in a well-ventilated area. Set up your fire pit use area outside, not inside or on a covered patio.

Cut any low-hanging branches if you have to build a fire pit in a wooded location or with a lot of foliage.

Make sure the surface you’re using for your fire pit is safe. Do not position it on a wood surface, and ensure the fire pit is leveled before lighting.

Make sure the bowl has a drain so it doesn’t fill when it rains. You can find some fire pits that come with a 1.5” hole pre-drilled for drainage and the gas pipe.

Burn nothing without a protecting layer of lava rock on the fire pit’s bottom. If you’re burning wood, cover the bottom with a layer of lava rock that’s at least 4-5 inches thick. Then, on top of the lava rock, add your firewood. Fill the fire pit with enough lava rock to cover the fire ring for gas burning.

Keep a fire extinguisher handy and wear protective gloves when lighting a fire pit and handling the fuel.

Cover the top with more lava rocks for fire until it reaches the very top of the pit to hide it.

Take the gas line through the bowl’s bottom and place the on/off valve near enough to the fire pit to make it easy to use. (Learn How Much Does It Cost To Level A Yard)

Even with the best precaution of utilizing lava rock to diffuse the heat, concrete fire pits can develop hairline fractures due to intense heat and cooling. To keep these cracks to a minimum, avoid using large, hot wood fires that burn to extremely high temperatures and are hotter than when you use gas and use lava rocks for a fire.

Some states and counties make it unlawful to burn wood, so check your local regulations.

How To Arrange Lava Rocks On A Gas Fire Pit

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