Skip to Content

Why Put Sand in the Bottom of a Fire Pit?

Why Put Sand in the Bottom of a Fire Pit?

Share this post:

This post may contain affiliate links. If you click an affiliate link and make a purchase, I may earn a commission. Also, as an Amazon Associate I earn from qualifying purchases.

Nothing beats the versatility and convenience of having a fire pit in your backyard. It can serve a huge variety of uses, especially as a bonfire for barbequing and enjoying s’mores.

But there’s one aspect of setting up fire pits that had many homeowners confused: lining it with sand at the bottom.

As weird as this technique seems, it’s highly recommended by experts, and many manufacturers even recommend it when using their metal fire pits.

In today’s article, I’ll help you clear out the confusion by explaining the purpose of this technique, and explore its pros and cons. So without further ado, let’s dive right in!

Why Is Sand Used in Fire Pits?

Fire On Ground

The reason for using sand in your fire pit is actually quite simple. Sand, especially silica-based types, is an excellent insulator of heat.

This means that it absorbs and distributes the heat throughout the entire base of the pit evenly, which protects the metal at the bottom of the bowl from the extreme heat of the fire.

The advantage of sand here is that it allows air to circulate between the granules. This is ideal for keeping the flame going because fire needs oxygen to thrive.

The point of insulating the fire pit here is that it protects the metal against those major levels of heat and prevents it from becoming concentrated in one specific area. 

Without sand, the metal at the bottom of the fire pit will quickly deteriorate and become quite brittle.

Do All Fire Pits Need Sand at the Bottom?

Stacked Firewood Inside A Fire Bowl

There are different types of fire pits out there, and while many brands recommend using sand at the bottom, not all of them do.

For instance, some fire pits will have holes built in at the bottom. That allows proper airflow from both above and below the bowl to keep the fire roaring.

Meanwhile, the holes should be enough to dispense the heat safely without needing sand. Even without the holes, the air still flows freely due to the bowl shape. 

In that case, some believe that adding sand can actually restrict that airflow and make it difficult for the fire to truly build.

Some fire pit owners prefer to not use sand. This is because wood fire ash can actually be used as a fertilizer. 

This means that the sand can be less than ideal for those looking to cultivate the wood ash for later use. 

In other words, it all comes down to personal preferences and the type of fire pit you have in your yard.

How Much Sand Should You Add to the Fire Pit?

First and foremost, you should always start by reading the manufacturer’s instructions. Each fire pit brand has unique instructions based on the materials used and its design.

It’s fairly common for most fire pits to recommend a sand layer of around 1 to 2 inches thick. However, the ideal thickness of the sand layer can still vary from one model to another. 

Additionally, some manufacturers mention in their instructions that their fire pits don’t need sand at the bottom.

What Are the Drawbacks of Using Sand with Fire Pits?

Fire Remnants In Rusty Fire Bowl

There are some reasons why you would not want to use sand in the bottom of a fire pit. Here’s a quick look at some of them.

Moisture Buildup

One of the natural properties of sand, especially silica, is that it’s quite hygroscopic. In other words, it tends to absorb and retain moisture from its surroundings, including water vapor in the air.

So even though the sand is meant to protect the bowl against the buildup of heat, it can actually make the bowl corrode a bit faster if it is exposed to moisture regularly.

Tedious Cleanup

As previously established, having access to wood ash can be beneficial for avid gardeners. 

The main problem here is that separating wood ash from sand can be quite a challenge. This is because sifting through wood ash and sand can be wasteful of both materials.

If you don’t need the wood ash, you can keep the sand in the fire pit for several months without having to clean it.

Poor Heat Circulation

As previously established, not all fire pits are created equally. Some types are made with holes in the bottom for drainage and circulation. 

In that case, adding sand to the bottom of the bowl is technically unnecessary, as it would reduce air circulation unnecessarily

Protecting Your Fire Pit

Keep in mind that the sand alone will not protect your fire pit. Yes, it will keep the bottom of the bowl protected from the extreme temperatures that a fire puts out. But that is all the protection that it will offer.

At the end of the day, you still need to take extra measures to keep your fire pit protected from damage. Here are some additional tips to preserve your fire pit in its original condition:

1 – Use a Fire Pit Cover

Rust is one of the major issues with metal fire pits that sand can’t prevent. It won’t only make the fire pit look outdated and unappealing, but it can also wear down the metal, causing holes and areas that chip off the fire pit.

To avoid this problem, try to keep it away from the elements when not in use for a long time. Alternatively, you can invest in a properly sized protective fire pit cover when you aren’t using it. 

2 – Apply a Coat of Rust-Resistant Spray

It is also a good idea to buy a high-temperature, rust-resistant spray, which is perfect for keeping the rust from potentially building up on both the interior and exterior of the bowl. 

This will ensure that your fire pit looks good and retains its functionality.

3 – Check the Moisture of the Sand Continuously

Lastly, if you do add sand to your fire pit, it is a good idea to check its moisture level every now and again. If the sand is too moist, consider dumping it out and replacing it.

That will be an extra measure towards keeping rust away and ensuring that your fire pit works optimally for a long time to come.

Final Thoughts

As you can see, sand is mainly used as a buffer for protecting fire pits from excessive heat. That being said, they’re not always necessary and don’t protect against elements.

A little bit of foresight and a protective cover can go a long way toward keeping your fire pit looking and working the way that it was meant to.


If you want more backyard tips including recipes, how-tos and more, make sure you subscribe to my youtube channel

Share this post: