Lava rock or fire glass? This is one question that all new fire pit owners are confronted with from the first day. So let’s settle this dilemma once and for all.
Both fire glass and lava rock have their advantages and disadvantages. Which one is better depends on what you are looking for. On average fire glass is better at dispersing heat, while lava rock is better at insulating.
While those are the main advantages, each one of them has other advantages as well, and let’s not forget about the disadvantages. So let’s take a closer look at each one of them, and see which one is better.
Table of Contents
Fire Glass
Fire glass is tempered glass with smooth polished surfaces used to evenly distribute heat throughout the fire pit’s burner pan. And it can be found in a huge variety of colors, shapes and textures.
The main advantage of fire glass is that it’s an excellent heat conductor. This means that the glass will quickly absorb the heat created by the fire pit, and then it will just as quickly release it into its surrounding.
This means that if you choose to use fire glass in your fire pit, you will be able to turn down the gas and still achieve the same heat as you would have with another medium. In short this means that with fire glass you will be able to save some money, while the total sum is not something considerable, over time the benefit will be visible.
Compared to lava rock, fire glass is also smaller, this means that the heat in the fire pit will be distributed more evenly.
Another big advantage of fire glass over lava rock is the huge range of colors in which it can be found.
One disadvantage is that despite it’s huge variety in colors and shapes, fire glass will always look artificial and unnatural. For a lot of people this might not be a problem, but some people prefer a more natural look for their fire pit, and this can’t be obtained with fire glass.
The biggest disadvantage of fire glass is tied to its biggest advantage, it’s excellent ability to disperse heat. Even if this might sound strange, but at certain temperatures fire pits can get damaged. When fire glass heats up it doesn’t only disperse heat outside of the fire pit, but also inside of it, and after some time your fire pit will get damaged and need to be repaired or completely changed.
How long until the fire glass will affect your fire pit depends on how high you turn the heat, and how often you use it, and for how long. So while saying something like: “using fire glass will shorten the lifespan of your fire pit to 5 years”, may or may not be true, one thing is clear, using fire glass will shorten the lifespan of your fire pit.
Those were the most important advantages and disadvantages of fire glass, now let’s move to lava rock.
Lava Rock
Lava rock is exactly what its name says, rock that has been formed from lava. This amazing origin story gives it some interesting properties that are quite different than those of fire glass.
The main advantage of lava rock is that it’s an amazing insulator, this means that unlike the fire glass that tends to overheat the fire pit, the lava rock actually protects the fire pit from the excessive heat.
But as you can imagine this advantage can turn into a disadvantage. While it’s good that the fire pit won’t be affected by the heat, this also means that the lava rock won’t disperse as much heat as fire glass. Don’t get me wrong, lava rock will still heat up and disperse heat, but not as much as fire glass.
The next advantage on the list can be an advantage or a disadvantage, depending on your preferences. Lava rock has a natural look, since it’s completely natural, and this can give it a great look. But some people might not like this look. So depending on your taste this can be either an advantage or disadvantage.
Now we will take a look at a few more direct comparisons like price and longevity.
Cost Comparison Between Fire Glass and Lava Rock
Lava rock can usually be purchased by bag. The price can vary between $10 and $50, depending on the weight of the bag. On average for a 10 lbs bag of lava rock you can expect to pay $20.
Just like lava rock, fire glass is also purchased by bag, the price of a bag can vary between $10 and $50. Most 10 lbs bags of fore glass will cost you around $20.
So this should mean that they cost the same, but that’s not quite the case. While you will pay the exact same amount for a 10 lbs bag, the surface that you can cover with that 10 lbs bag will not be the same.
Due to their different weight, you will need 20 lbs of fire glass to cover the surface that you would cover with just 10 lbs of lava rock. This basically means that fire glass is actually two times more expensive.
Another important aspect to take into consideration is that the prices of fire glass can increase drastically if you want a rarer color or model. If you are fine with a light blue, fire glass that simply looks like glass that has been broken, you will pay only $20 for a bag, but if you want an intense purple that has smooth edges you will probably end up paying $50 per bag.
Lava rock on the other hand doesn’t have too many colors or shapes, so there is little to no difference in the price.
Which Lasts Longer Fire Glass or Lava Rock?
Another important aspect to take into consideration when choosing a medium for your fire pit is how long it will take until you have to change it.
Lava rock is a natural material that does not decompose. This makes it highly desirable and valuable as a material for fire pits.
The only problem that lava rocks have is that they can be affected by moisture. Lava rocks can absorb a lot of moisture and this can make them crack.
On the other hand fire glass doesn’t have any problem with humidity, but it’s a lot more fragile than lava rock. As the mane implies fire glass is glass, even if it’s not as fragile as a cup made out of glass, it can still break if not handled with care.
Overall both of them are quite resistant and, neither will break as long as you don’t hit them with a hammer. So you shouldn’t worry about how much they will last, there are other things more important to take into consideration.
Final Thoughts and Comparison Table
Here is a table containing a resume of everything that we talked about in this article.
| Fire Glass | Lava Rock |
| Huge variety of colors, shapes and textures | Little variety |
| Smaller | Bigger |
| Artificial | Natural material |
| Look artificial and unnatural | Rustic and natural look |
| Excellent ability to disperse heat | Doesn’t excel at dispersing heat |
| Excellent heat conductor | An amazing insulator |
| Doesn’t absorb moisture | Absorb moisture |
| Expensive | Cheap |
| Does not burn or melt | Naturally durable material |
| After some timer fire pit will get damaged by the heat | Fire pit won’t be affected by the heat |
So fire glass or lava rock? As you can probably guess there is no right or wrong answer. But there is one option that is better than fire glass or lava rock, and that is fire glass and lava rock. If you combine them properly you can get all of their advantages and none of the disadvantages.
But you can’t just simply throw a bunch of fire glass and lava rocks in the fire pit, you have to layer them accordingly. If you want more information on how to do this properly, check out this article, where you will learn everything that there is about combining fire glass and lava rock: Can You Mix Lava Rock and Fire Glass in a Fire Pit? (With Pictures)
In the end of the article I will leave you with some of the most common questions and problems that people are faced with when owning a fire pit. Hopefully this will help you avoid some of the biggest mistakes people make when owning a fire pit, and save you some money.
Common Questions
How do I prevent rust from appearing on my fire pit? In order to prevent rust you can:
- Move the fire pit in a dry room, or any place with a roof should prevent most rust from appearing.
- Cover your fire pit using a metal or wooden lid, or a synthetic cover. But make sure that the fire pit has cooled off before you cover it.
- Removing the ash from the fire pit is also very important, as ash absorbs a lot of humidity from the air.
- The most important thing that you can do is to regularly clean and inspect the fire pit.
How do I remove rust from a fire pit? To remove rust from a fire pit you can use:
- Vinegar
- Lemon juice
- Soft drinks
- Baking soda
- Potatoes
- A mix of them
- Commercial products like: WD-40 and CLR
After you remove the rust you should get some Sandpaper, Spray Sealant, Spray Paint. After that you should remove all the paint using a coarse grit sandpaper, then use a finer sandpaper and remove all scratches. Apply a thin coat of sealant, after it dries apply the pain, and then another coat of sealant. Make sure that you try to make the coatings as even as possible, otherwise the paint will come off.
Do propane gas fire pits smell bad? Propane fire pits shouldn’t smell bad. You might feel a small hint of gas when you turn the fire pit on, but that should be the only bad smell that you feel.
If the bad smell persists there might be a problem with the fire pit, the regulator, the propane tank or dust.
To check if the regulator of the tank has a problem you can make some foam with some water and soap and spread it where they connect. If bubbles start to form, then you have a gas leak. In which case you can try to see if the gasket is damaged and if the regulator is tightly screwed. If this doesn’t solve the problem you should call somebody to check the fire pit.
If the gas smell appears when the fire pit is turned off, it usually means that the fire pit is broken, in which case you should call somebody to repair it.
Another cause for the bad smell can be dust. Excessive dust will usually give off a burnt smell. This smell usually tends to disappear after some time, but in some cases the residu can stick to the rocks that fill the fire pit, in which case you will have to wash the rocks.
In case you have a technical problem the best thing that you can do is call somebody that is trained to deal with those kinds of problems. Don’t try to repair them yourself, it can be very dangerous.
How long do fire pits last? A fire pit can last anywhere from one year to a lifetime. It all depends on how well you maintain it.
In the case of wood burning fire one of the most important things that matter is what you are burning. Things like magazines contain chemicals that can damage the fire pit. Wood that has been painted or treated in any way will also damage the fire pit. So only burning firewood will increase the lifespan of your firepit.
Removing the ashes is also very important. Ashes absorb humidity from the air, so letting them sit in the fire pit for long periods of time is like having your fire pit filled with water.
In the case of gas fire pits it’s extremely important to dust them off. Dust doesn’t only leave an unpleasant smell but over time it can damage the interior of the fire pit.
For both types of fire pits it is also extremely important how you store them, leaving them uncovered year round, will drastically reduce their lifespan.