The bottom of a fire pit can be made of various materials. This article will provide a comprehensive list of materials and emphasize the most important factors to consider.

Burning Woods in a Fire PitTo make sure that you have all that you need to know when selecting the best material for your fire pit, we will compare the materials based on several criteria.

After reading this article, you will be more than ready to build a fire pit, and with our added maintenance tips, you will learn how to keep it in top shape and get the most out of it.

What To Use in the Bottom of a Fire Pit

For your fire pit bottom you can use materials such as dirt, gravel, sand, stones and lava rocks, and fire glass. There are different options that you may choose from, ranging from those that are free and readily available to more expensive choices that are challenging to find. 

– Dirt

1. DirtLet us start with the material that can be found almost anywhere and is completely free: dirt. The latter is convenient, easy to use, and offers heat resistance.

Using them as the material at the bottom of the pit will require maintenance as some of the organic materials in the dirt will burn and tend to mix with ash, which will create a mess when wet that will require the use of a shovel to clean up.

Another disadvantage is that you need to refill them each time you use the fire pit. In addition, if the fire pit already has holes at the bottom, dirt is not a good idea to use as it may obstruct airflow by clogging the holes.

In a nutshell, dirt is the most economical material to use, but it has its fair share of disadvantages you need to compensate for.

  • Price per 10 pounds: Free
  • Availability: Easily accessible
  • Risk: Low (safe to use)
  • Heat Resistance: Low
  • Maintenance: High (requires refilling at each use and scooping out the muck)
  • Aesthetics: Poor

– Gravel

2. GravelAnother great material to consider is gravel under fire pit. It is a common material used in landscaping, so it is easily available and attractive, too. It is composed of small, shredded rocks that can be easily scattered. It is great to use for a fire pit’s bottom as it keeps the pit warm while preventing the base from burning.

There are many varieties of gravel, and if you are not selective about it, you can just put in enough to cover a small portion of the fire pit and add more later.

The most commonly used is pea gravel, as it doesn’t cost much. However, one should be cautious, too, as gravel is not intended to sustain high temperatures for an extended period.

  • price per 10 pounds: $0.8 to $1.4
  • Availability: Easily accessible as they are commonly used in landscaping
  • Risk: Moderate
  • Heat Resistance: Low (not intended to withstand high temperature for an extended period)
  • Maintenance: Low
  • Aesthetics: Good

– Sand

3. SandUp next is something that is commonly used due to several of its advantages. Sand is a cheap material to use, and almost any kind of sand will work well as a bottom material for a fire pit. It is easy to use and is known to absorb heat and distribute it evenly around the pit.

The sand serves as an insulator, especially if using a metal fire pit. It plays an important role in preserving the metal at the bottom of the bowl. Without sand, the heat can become concentrated on one region alone, which can lead to the deterioration of the metal.

Sand, being a fire-resistant material, is also great at keeping embers from scattering. Additionally, it can be used as a holder to start a fire. You can simply stack the wood in the sand and keep the small pieces of wood in place.

However, sand is not for everyone. While air can flow through a fire pit bowl without openings, others claim that adding sand to it will obstruct airflow and make it harder to keep a fire.

Furthermore, some people, particularly gardeners, prefer not to use sand in their fire pits because firewood ashes can be used as a fertilizer, but not when it is mixed with sand, which necessitates removing it and replacing it with a new layer of sand now and then.

Another disadvantage is that sand holds moisture, so while it is supposed to protect the bowl from heat accumulation, it can contribute to the corrosion of the bowl if it is exposed to moisture regularly.

Depending on the climate in your area, it is best to periodically check the moisture of the sand in your pit. Discard and replenish it accordingly when it is too moist.

Nonetheless, the best thing about using sand in bottom of fire pit is that, for a relatively cheap material, it lasts a long time. If maintained and used properly, it will last for decades and will keep your firepit fair-looking.

  • Price per 10 pounds: $20 to $25
  • Availability: Easily accessible
  • Risk: Low (safe to use)
  • Heat Resistance: High
  • Maintenance: Moderate (you may need to replace a new layer of sand every now and then)
  • Aesthetics: Fair

– Stones or Rocks

3. Stones or RocksStones or rocks, which are also readily available, are another inexpensive alternative for the bottom of a fire pit, as long as the stones are small enough to form a sturdy bed of fire pit stones. Stones also provide an additional layer of protection from sand or soil at the bottom of metal fire pit; plus, they also look great.

The stones should be the size of a dime or smaller, as this will considerably lessen the chances of them exploding. Larger stones, especially damp ones, have the potential to explode. When heated, the moisture trapped inside expands, causing the stone to crack and sometimes explode.

The ideal types of rocks to use are marble, granite, or any hard rocks that are denser and will likely absorb water, resulting in a lower chance of erupting.

Limestone, river rocks, sandstone, and pumice are what should be avoided. Furthermore, if your fire pit has stones, it is best to cover them during bad weather to keep them dry and avoid incidents of exploding stones when you use them.

  • Price per 10 pounds: $20 to $30
  • Availability: Easily accessible
  • Risk: Moderate (need to be cautious as not all types of stones are safe to use; bigger ones tend to explode when heated especially when damp)
  • Heat Resistance: Moderate
  • Maintenance: Low
  • Aesthetics: Good


– Magma Lava Rocks

4. Volcanic RocksPlacing magma lava rocks is a great alternative if you want something that will last a long time and won’t need to be replaced. Based on what it’s called, “lava” rocks are made of solidified magma, which offers a high level of heat resistance without cracking or exploding.

They can retain heat for several hours while the highly permeable surface of the rocks allows water to drain, which keeps them dry. These characteristics make them an ideal material to use in a fire pit.

Adding to their advantages is that they are aesthetically pleasing. With their unique color, they have a natural exotic appearance that adds to the rustic feel of the fire pit base. However, as these are not man-made, they can be challenging to find in your local stores.

But do not fret, there are a lot of online shops that sell magma lava rocks at reasonable prices. But even then, it is expected to be more expensive than sand and dirt, which are free. 

  • Price per 10 pounds: $20 to $50
  • Availability: Hard to find a physical store that sells them (most great deals can be found online)
  • Risk: Low (safe to use)
  • Heat Resistance: High
  • Maintenance: Low
  • Aesthetics: Excellent (unique appearance makes a great decoration to any fire pit)

– Firepit Glass


So far, we’ve talked about freely available, low-cost, and medium-cost materials. Now, we’ll move on to the costliest item on the list: fire pit glass. It consists of small gravel-like stones that are made of glass. It is one of the more expensive materials, but it is also one of the safest.

Since they are specifically made to be used in the pit, they are built to withstand extreme heat and have almost no risk of exploding. They are a bit flammable but do not spread the fire. They keep the heat concentrated at the bottom of the pit and help the fire keep burning for hours.

Firepit glass is also easy to find as there are a lot of options available on the market. They come in a wide variety of designs and colors, which will incredibly boost the aesthetics of any fire pit.

The reflection of the flames on the glass provides a spectacular light show. Adding to its advantages is that it can last for years as it never wears off. It only requires very little maintenance.

  • Price per 10 pounds: starts at $30 but can cost as much as $100
  • Availability: Easily accessible and has a wide selection of different designs and colors
  • Risk: Low (designed to be used in a fire pit)
  • Heat Resistance: High (created to withstand extreme heat)
  • Maintenance: Low
  • Aesthetics: Excellent

We included these two materials even though they are not specifically used for the bottom of a firepit but are often used in the construction of the whole firepit.

– Bricks

5. Bricks

Bricks are another material to consider not just for the bottom of a fire pit but to build the fire pit itself. However, not all types of bricks are recommended. Cinder blocks and other regular bricks can be used; however, they will deteriorate with time.

A unique form of brick known as “fire bricks” is designed to endure tremendous heat (up to 1800 degrees Fahrenheit), similar to brick ovens, making it a safe alternative to use that can extend the life of a fire pit. However, coming at a price, fire bricks can also elevate the aesthetics of your fire pit.

  • Price: $3.75 per piece (when building a regular 36-inch fire pit, it needs around 80 pieces of bricks, so around $300)
  • Availability: Easily accessible
  • Risk: Low (safe to use)
  • Heat Resistance: High (fire bricks are designed to withstand extreme heat)
  • Maintenance: Low
  • Aesthetic: Excellent

– Concrete

6. ConcreteIf you already have a concrete patio and are planning to build a fire pit, you can build it on the concrete, but there are a couple of things to consider. The heat of the flames can cause the concrete to crack, so you should place the fire pit on concrete so that you don’t mind getting damaged. Consequently, it will need to be restored, which can be a bit pricey.

While concrete is often overlooked as a fire pit bottom, a concrete slab is a wise alternative. Concrete is a good fire-resistant material that can last a lifetime and provide enough heat to keep the fire lit for several hours.

  • Price: Around $110
  • Availability: Easily accessible
  • Risk: Low
  • Heat Resistance: Moderate
  • Maintenance: Low
  • Aesthetics: Fair

Now that you know what material to use in your fire pit to suit your style and budget, let us give you some maintenance tips so you can get the most out of your fire pit.

Fire Pit Maintenance Tips 

Outdoor fire pits, in general, do not require extensive maintenance, but understanding how to do so will guarantee that you can enjoy your fire pit for as long as possible. First, it is recommended to purchase a basic fireplace toolbox that contains a long poker, an ash scooper, and log tongs, which can make maintaining the fire pit much easier.

– Keep It Clean

It is critical to keep your fire pits clean by removing the ashes. Allowing them to sit for an extended period can erode the walls of your firepit. It is best to scoop them out regularly to avoid long-term damage.

However, be cautious because ashes can retain heat for several days, posing a fire risk. To be safe, remove them after two or three days. You can put them in a bag and throw them away with your regular trash, or you can use them in your garden. 

– Take Into Account Your Fuel Source

Even if it’s tempting, avoid burning any trash in your fire pits. The burned organic matter in it might be harmful to your fire pit. It is best to use mature split wood as it creates less buildup over time. 

– Seal Cracks

Flooding fire pits with water to extinguish a fire causes temperature fluctuations in the pit, which can cause damage to your firepit. While it is preferable to let fires burn out naturally, a bucket of water should always be kept nearby as a safety precaution. Periodic maintenance should include checking for cracks and patching them. There are a variety of fillers that can withstand high temperatures. 

– Use a Cover

Water and moisture will make it hard to start and maintain a fire in the pit. Furthermore, when a damp stone is heated, it can explode. To avoid this, it is a good idea to invest in a fire pit cover. It could be as simple as a vinyl cover, but keep in mind the weather in your area.

Photography of Wood Burning on Fire Pit


Building a fire pit in your backyard or garden is a terrific way to add to the appeal of your outdoor space. With the list we’ve provided, you’ll be able to figure out which materials will work best for you.

Let the table below help you compare the materials we covered in this article. 

  • Dirt is the cheapest and most readily available material. It can simply be scooped out from the outside. The ash, on the other hand, tends to combine with the burned organic stuff in the dirt, resulting in a terrible mess that requires a shovel to clean up.
  • Gravel is the second-most inexpensive material that requires low maintenance.
  • Sand is the most popular choice for moderately priced materials like sand, stones, and lava rocks. Some fire pit kits even recommend it due to the added protection it provides at the bottom of your fire pit.
  • Designed to be used on fire pits, fire bricks and fire pit glass are excellent choices, though they can be a bit pricey.
  • Concrete is the way to go if you want a fire pit that will last a lifetime. Concrete, while not as appealing as lava rocks, fire pit glass, or fire bricks in terms of aesthetics, is low-risk and low-maintenance.

Now that you know what materials you can use to line the bottom of your fire pit and how to maintain it, you can relax and enjoy the warmth and fun atmosphere a fire pit creates with your family.


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