A fire pit can be the perfect addition to your backyard on a chilly night, bringing your friends and family together to make memories. However, fire pit media, like lava rocks, can be necessary for your fire pit, especially if you have a gas fire pit. You may be curious about which type of fire pit media—lava rocks, fire glass, or fire stones—is best.
Below, we let you know what these media are and how they stand up against one another.
All three are great options to protect and decorate your fire pit in your backyard to make it a central gathering point throughout the year. If you want the cheapest option, go with lava rocks, but they may not last as long as fire glass or fire stones. If you want a variety of choices and a longer life, you should consider fire glass or fire stones. If you want a fire pit media that will retain and disperse heat the best, purchase fire glass.
There are several similarities between fire glass, lava rock, and fire stones. For instance, all media is safe to use in fire pits. Each fire pit media is available in various attractive options, including color, size, shape, and style.
The main differences between these three types of fire pit media are heat retention and cost. Fire glass will retain and disperse heat more effectively. However, lava rock is cheaper to purchase, though it doesn’t last as long as fire glass or fire stones.
Fire Pit Media Basics
Lava rocks, fire glass, and fire stones are three of the most popular types of fire pit media. Available in an assortment of styles, shapes, and sizes, fire pit media is a decorative add-on to the fire pit burner of a gas (propane or natural gas) fire pit. Fire pit media is used to conceal the burner of a fire pit. In doing so, the media also help to protect the burner from the elements and debris.
In some cases, these media can be used in a wood-burning fire pit. However, before doing so, consult with fire media manufacturer guidelines/recommendations and fire pit manufacturer guidelines/recommendations.
What Are Lava Rocks?
Offering a natural look, lava rock is a naturally occurring rock that is porous. As suggested by the name, lava rock comes from within the crust of the Earth. The molten rock from a volcano eruption cools and turns into the porous and ingenious rock we know as lava rock.
Lava rock is mined from several ancient volcanoes in California, New Mexico, and other western states. This rock is known to be as old as 2,000 years! Available in three main colors, lava rock is typically red, black, or brown, and it is covered in small holes. It could be compared to a hard sponge.
Because lava rock comes from volcanoes, it has the potential to withstand incredibly high temperatures without emitting toxins or smoke, making it a non-toxic option for your gas fire pit.
What is Fire Glass?
A manmade material, fire glass is made from fragments of tempered glass, creating a translucent, heat-resistant media for fire pits. To remove the sharp edges, fire pit glass is tumbled and polished. This creates soft, finished edges and a polished texture. It is available in non-reflective, semi-reflective, and reflective finishes.
Fire glass will not shatter, melt, or burn. Like lava rock, fire glass is non-toxic. Fire glass has been known to emit as much as four times the amount of heat as wood, creating a more fuel-efficient and cleaner option for a fire pit.
What are Fire Stones?
Fire stones are stones made to look like the real thing, but they are fire safe, as they are made from a heat-resistant ceramic material. They have a smooth surface and are available in various shapes, sizes, and colors. They are made from a mixture of ceramic and cement, which makes them incredibly durable.
Real stones can absorb water and pop when heated, which can be dangerous, but fire stones will not due to their construction. When choosing to use fire stones, they must be placed strategically in the fire pit, so there is sufficient airflow, allowing taller and fuller flames.
Below we compare lava rocks, fire glass, and ceramic fire stones on six key dimensions:
Heat retention and dispersion: This category focuses on how well the fire pit media can reflect and absorb heat. Which is better for getting more heat from your fire pit?
Appearance / Variety: This category is about how the fire pit media looks and the availability of style variety. Which media looks best?
Maintenance: This category focuses on ease of maintenance. Which media offers the least maintenance?
Durability: This category is about how long the fire pit media will last. Does one last longer than the others?
Safety: This category focuses on any potential safety concerns associated with the fire pit media. Which one is safest to use?
Price: This category is all about the cost of the media, including upfront and ongoing costs. Which is more affordable than the others?
#1: Heat retention and dispersion
Winner: Fire glass
All options are good conductors, but fire glass is better at absorbing and dispersing heat because of its reflective surface. Since fire glass has a better ability to absorb and transmit heat, it means less use of gas and more warmth from your fire pit.
Lava rocks do not fair as well as fire glass. The porous nature of lava rocks means they don’t retain heat as long or radiate it as well. Using smaller lava rocks or combining them with fire glass may help in heat conductivity and dispersion. This can also help the lava rocks heat evenly.
Fire stones can retain heat well, especially after the burner has been switched off. However, because they can restrict airflow needed for full flames, the heat retention and dispersion simply aren’t as desirable as fire glass.
#2: Appearance / Variety
Winner: Beauty is in the eye of the beholder, so there is no real winner, but fire glass has more variety than other fire media types.
Fire glass can come in a wide array of colors and sizes. They can be smooth or rough cut, and they provide a clean and modern look. Due to the wide assortment of options, finding something that matches your tastes won’t be difficult.
Lava rocks are typically only available in brown, black, or red colors due to this media being completely natural. Despite this limited availability, lava rocks provide an organic, rustic look for your outdoor space that other media cannot provide.
Fire stones are smooth and come in various shapes and sizes to mimic the appearance of natural rock. There is some color variation, and fire stones provide a clean, modern, and contemporary look.
Winner: Slight edge to lava rocks because they mask soot.
Fire glass will require maintenance, as you will see soot marks after several uses. This soot can be cleaned with a rag, water, or dish soap. Another option is to use a 1:1 water and vinegar solution. Make sure to allow the fire glass to dry completely before placing it back in the fire pit. Alternatively, you can simply mix around the fire glass if needed to conceal those with soot.
In addition, the sunlight may fade the fire glass, especially if it is a darker color. A stainless steel cover can be used during the summer to combat this.
Lava rock’s dark, natural appearance helps hide or cover soot marks. To help lava rocks last longer, use water to wash them regularly. Like fire glass, lava rock must be completely dry before being placed back into the pit. Lava rock can fade over time, but a cover can help prevent this.
Fire stones will show soot, too, especially on lighter colors. However, as a general rule, very little maintenance is required to keep fire stones looking great. A quick wipe-down with a rag will remove the built-up soot.
So, when properly maintained, all types of fire pit media are good options when it comes to maintenance.
Winner: Fire glass and fire stones
Fire glass and fire stones should last several years, especially when maintained properly. On the other hand, lava rocks will last about two to four years before the color fades and the stone begins to deteriorate. At this point, the lava rock can benefit from being replaced. Fire glass and fire stones are unlikely to discolor or fade as quickly as lava rock.
Winner: Slight edge to fire glass and stones
All three are completely safe to use in a fire pit, as they all remain stable at extremely high temperatures. The only real concern is if the media gets wet. If media is not allowed to properly dry before using, it may pop or explode, which can cause harm to anyone who is near the fire pit. This tends to be a higher risk with lava rocks because they are made of porous material.
Therefore, it is imperative to ensure that lava rocks, fire glass, and fire stones are completely dry before use. When your fire pit is not in use, make sure to use a lid or cover to protect the fire pit.
Winner: Lava rocks are generally cheaper for the initial purchase, but continually replacing them over the long run will add up.
Lava rocks generally cost around $10 to $20 per 10 lb. bag, making it the more cost-effective option. However, this price can vary depending on the size and color of the rocks. Lava rock does need to be replaced every few years, which means the cost can add up over the life of your fire pit. Because lava rocks can be bigger than some fire glass and fire stone options, it won’t take nearly as much to fill up your fire pit.
Fire glass runs about $20 to $40 per 10 lb. bag. Again, the price can vary based on style, color, size, etc. Even though more fire glass is needed to fill up a fire pit, it is easy to get your money’s worth since fire glass can last for years. This is especially true when you consider that fire glass will not need as much gas to disperse heat, allowing you to benefit from gas savings.
Unlike lava rocks and fire glass, fire stones are not generally sold by the pound. Instead, fire stones are sold by the number of stones in a set. You can expect to pay between $50 and $75 for a set of 15 stones. Of course, this price can vary based on shape and size. The good news is that fire stones can last for many years.
Can I interchange lava rock, fire glass, or fire stones on my fire pit?
Yes, fire stones, fire glass, and lava rock can be interchanged if you prefer the look of one over the other. However, consult with fire pit manufacturer guidelines and fire media guidelines to see if there are any restrictions on using one media over another.
Can I simultaneously use lava rock, fire glass, and fire stones in my fire pit?
Yes, it is possible to combine fire glass with fire stones and lava rock. However, all three might be too much. A popular method is to use lava rock as a base and then add fire stones or fire glass on top.
How much fire glass or lava rock does my fire pit need?
With lava rock, for each square foot, you need about 3.5 lbs. for an inch depth of lava rock. With fire glass, for each square foot, you need about 7.5 lbs. for an inch depth of fire glass. Consult this calculator to help you determine the right amount for your fire pit.
How high should my lava rock, fire glass, or fire stones be above my burner?
Generally, it would be best to place fire pit media no more than 1″ to allow appropriate airflow to reach the burner. Consult your manufacturer’s guide for specific information regarding your fire pit.
Fire glass, lava rocks, and fire stones can all provide a very attractive top to your fire pit. Each media option brings something unique to the table, so when it comes down to which fire pit media you should use, it comes down to personal preference, individual tastes, décor, and budget. Regardless of the option you choose, you will have a protective and stylish topping for your backyard fire pit.