Will Concrete Explode in a Fire Pit? (6 Surprising Reasons)

A fire pit is an excellent addition to your backyard design. But, there are risks of explosion if you do not choose suitable materials.

Yes, concrete blocks or rocks can explode in a fire pit. This can happen when the temperatures become too high and water vapors are entrapped inside concrete pores and pressure is built. Eventually, the pressure exceeds the tensile strength of concrete and boom! You will witness an explosion.

Waterproofing the concrete and other measures can significantly reduce the chances of an exploding fire pit.

Will Concrete Explode in a Fire Pit

This detailed article will not only tell you, “will concrete explode in a fire pit”, but also will give you some insights into why they explode and what safety measures you can adopt. 

Why Did My Fire Pit Explode?

In most cases, concrete fire pits get expanded, and cracks can appear. 

However, when there is a high temperature and water vapors can’t escape from concrete, an outburst can happen. 

Will Concrete Explode in a Fire Pit

Besides that, there are other reasons that may contribute to your fire pit explosion.

Moist Rocks

Moist rocks are another reason for exploding fire pits. The water inside the rock boils and the pressure from the steam causes the rocks to explode in the fire pit.

If you want to avoid an explosion of rocks in your fire pit then you have two options. The first one is to remove the rock and the second option is to dry them out.

You can also put some coal on top of the rocks and make the fire slow. With this trick exploding will eventually stop.

Giving the rocks a hot sun bath can also work but this is not that effective. 

Over Fueling The Fire Pit

In order to get more heat some people put too much fuel in the fire pit. This can produce a lot of gases and ultimately can lead to an explosion.

Also, putting the wrong type of fuel, which can produce excessive heat, can damage your fire pit. Do not use coal as it produces too much heat and can damage or ruin your fire pit. Also, do not use softwood, because it creates a lot of unnecessary gases which might cause an explosion.

That is why it is important to put a suitable amount of fuel in the fire pit. 

Firewood and natural gas are one of the best sources of fuel for your fire pit.

Lack Of Ventilation

 poor ventilation can cause your fire pit to explode. When there is no room for the gases to escape, then an explosion can happen. 

If your ventilation is poor and you see a lot of smoke, then be careful, because an explosion may be coming on its way.

Will Concrete Explode in a Fire Pit

How to prevent fire pit explosions?

To prevent fire pit explosions, it is important to follow the manufacturer’s instructions when using it. This includes using the appropriate fuel, such as natural gas or propane and avoiding overfilling the fire pit.

In addition, it is important to properly maintain the fire pit, including regularly cleaning it and checking for any damage or leaks.

To reduce the risk of gas build-up, it is also important to ensure that the fire pit is properly ventilated.

Will A Fire Pit Damage or Ruin Concrete?

A fire pit can damage or ruin concrete. When concrete is exposed to fire, it can expand, and you will see cracks in it after some time.

Exposing concrete directly to fire does make the problem. However, if you raise your fire pit above or put some insulation between the concrete and the fire pit, then you can protect it.

Also, make sure that you put some sand on the concrete, so that pit doesn’t leave any black spots on it.

Will Concrete Pavers Explode in The Fire?

 Yes, concrete pavers can explode if water is trapped inside them. However, in most cases, it will crack and get fragmented over time.

In order to protect your pavers from exploding, lining them with a metal sheet will work. 

In case you are planning to build a big fire pit then an outer lining of fire breaks can also protect your pavers from cracking and exploding.

Will Concrete Blocks Explode in a Fire Pit?

Concrete blocks can explode in a fire pit if enough water is trapped inside the bocks and there is no way for the steam to get out.

Concrete blocks that are dense and not porous can easily explode.

You can use tinder blocks but make sure that they are porous so that steam can easily get out from them. 

Retaining wall blocks with a ring inside them is also a good idea for your fire pit.

Will Rocks Explode in Fire?

Yes, rocks will explode in your fire pit, if they are moist. Usually, marine rocks that have gathered a lot of moisture over the years and are eroded into well-rounded shapes can explode easily in a fire pit.

Granite rocks that are being crushed are one of the best options that you can use in your fire pit. Lava rocks are also a very good choice. The best thing about lack rocks they are quite cheap.

Avoid porous rocks; they can hold water inside them and are prone to explosion.

 Also, stay away from limestone. It has thin layers and can pop easily even under intermediate temperatures. Instead of rocks, you can also try fire glass in your fire pit.

Does Concrete Melt in a Fire?

Concrete does not melt in a fire pit, however, it can dehydrate and cracks can appear in it.

When concrete is exposed to extreme heat it will get damaged and can often change its color.  

Under high temperatures, concrete can also sometimes explode.

The splints that come from these explosions might hurt you but it is not vigorous like dynamite explosions. Anyhow it can hurt you.

Final Thoughts

So, will concrete explode in a fire pit? The answer is that it can explode. You need to take care of the following things before enjoying it.

  • Use an insulating material such as a metal ring or a sheet on the inner surface of the concrete blocks.  This will protect concrete from exploding and cracking.
  • Use Lava rocks instead of ordinary marine or river rocks.
  • Also, make sure that you keep a distance between the fire pit and the concrete. This will prevent the concrete from cracking and spalling.
  • Use the right kind of fuel in your fire pit.  do not use a fuel that is too smoky or that can generate too much heat.

Fire pets do not blast that often, but when it does, the main reason is homemade projects that are executed quite poorly.


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