Can I Use Lava Rocks in a Wood Burning Fire Pit

By Mike

October 24, 2020

When my sister and brother-in-law bought their house, one of the things the whole family was very excited for was the potential in their backyard. Everyone had suggestions. One of the first things my brother-in-law did was build a fire pit. Envisioning wonderful evenings around the fire, I told him he should get some lava rocks and he was surprised. He asked me, “Can you use lava rocks in a wood burning fire pit?” Knowing that they would look really good with the rest of his landscaping, I decided to check it out for him.

It turns out that lava rocks are one of the best choices in terms of safety and practicality. They are also one of the best options when it comes to budget. Nature has designed them perfectly to absorb heat and provide drainage and airflow to give you a cleaner-burning wood fire. 

There are several options for wood burning fire pits, and depending on the location and construction materials, how you choose to line and fill your fire pit is going to vary. Both in-ground and free-standing fire pits benefit from some fill at the bottom and there are a few options that will work.

Let’s take a look at some of the benefits of choosing lava rocks in your fire pit!

Are Lava Rocks Best for Inside a Fire Pit

While there are some other types of rock that might seem more aesthetically pleasing than lava rocks, you have to be very careful, because many general rock options are NOT safe under the high heat of a fire. Choosing a fire-safe material is critical when setting up your fire pit.

The two options that are the most highly recommended for use in fire pits are lava rocks and fire glass, and they both have a lot going for them. Both options come in a variety of shapes, sizes, and colors. Both are also good at evenly distributing heat. What you choose is ultimately going to come down to what you like, but there are some benefits to lava rocks, especially when it comes to wood burning fire pits.

Can Lava Rocks Take the Heat

Lava rocks were created inside volcanoes – they are designed by nature to stand up to the high temperatures of a fire pit. They have natural heat retention properties that help distribute heat evenly. They are also naturally fire resistant, so they provide some insulation and protection for the other materials of your fire pit. This is especially useful if you’re using a free-standing fire pit.

Their ability to take the heat is also a factor when it comes to appearance. They keep their natural color even under high heat and exposure to the elements. This means there’s not a lot of maintenance needed once you’ve got them in.

When it comes to heat, something to keep in mind is that the smaller the pieces of lava rock, the more evenly they will disperse the heat of your fire. If the heating capability of the fire pit is an important factor in your considerations, then go for a smaller size lava rock.

All About the Airflow and Drainage for Fire Pits

When it comes to a good wood fire, one of the key elements is airflow. Good air flow and you’ll have a lovely, hot-burning, clean fire; bad airflow and your fire will be smokey and hard to keep going. Lava rocks are particularly good for creating a good airflow environment for your fire to thrive in.

Unlike gas fire pits, airflow is something that you need to be aware of and plan for with a wood burning fire pit. The space between the pieces of the filler you choose can make a big difference to the airflow. With lava rocks, their volume and the space between the rocks often leaves more room for air to move through than with other types of filler. The dry and porous nature of the rocks also provides a good situation for airflow, which is a great benefit for a wood fire. 

Similar to airflow, having a well-drained fire pit makes a big difference to a good wood fire. Water is the enemy of fire and so whether it’s out the bottom of a free-standing fire pit or an in-ground, any water needs to move far away from where the fire is. 

Lava rocks leave lots of space for water to drain off and out of the fire pit. Its quick-drying nature also aids in the drainage situation.

Are Lava Rocks Expensive

When it comes to cost, lava rocks are one of the best fillers for the bottom of your fire pit. At a base level it is less expensive by weight. This is even more key when you take into account the fact that generally you need much less weight to fill up the same space as other filler options – often two to three times less! 

Depending on the size of your fire pit, this can make a huge difference when it comes to the cost. If you’re going with a bigger fire pit, and filling it up with lava rocks will probably cost half of what fire glass would, that savings could be significant. These rocks are also light and easy to work with, so there is no need for installation help and the accompanying fees.

Lava rock also is very durable, holding up well to both the heat of your fires and to the general elements, so it doesn’t need to be replaced often. When you do need to replace it, the lower price once again makes it a budget-friendly option.

Lava Rocks Look Good

Of course this aspect is much more a matter of personal taste, but the rougher surface of lava rocks is a good match visually for the more natural look of a wood fire. The many sizes and colors that the rocks are available in allows for a lot of flexibility in landscaping style. There is something for everyone! 

If you’ve got a large area to cover in your fire pit, a larger size lava rock works better for scale. There are small rocks for a portable fire bowl. The various colors- shades of red, brown, black, and grey provide contrast or complement to your landscaping and outdoor furniture choices. There are even shaped and smoothed lava rocks for a more subtle and classy look.

Avoid Exploding Rocks

Exploding rocks are a problem everyone definitely wants to avoid! The key to this is to keep them dry. One of the reasons to avoid fillers like gravel or even pretty river rocks is that they often have absorbed moisture and when the water gets hot and expands, it can cause them to blow apart. This is not the way to liven up a backyard party!

While lava rocks don’t hold moisture and dry quickly, they can explode if they’re not all the way dry. However rare and unusual it is for lava rock to explode, it’s better safe than sorry, so it’s a good idea to cover your fire pit when you’re not using it and to let it dry completely if it does get wet.

Conclusion 

Now you know that you can use lava rocks in a wood burning fire pit, and they are a great choice! Though there are several options, lava rocks are an economical choice, providing a layer of protection, allowing for neat drainage, and improving the airflow when you’ve got that blaze going. And they look great while they’re being so useful!

About the author

Hi I'm Mike! I'm the owner, writer, and sometimes editor of Foundedproject.com. Being a new homeowner can be a little daunting, which is why I created this blog. I write about problems that a new home owner might run into. 

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