Many of today’s gas powered fire pits come with either ceramic logs or lava rocks as a standard. Unless you custom order specific logs or rocks, chances are the look is not exactly, shall we say, aesthetically invigorating. Enter the modern lava rock. A recent entry into the decorative fire pit lava rock market is the smooth lava rock, available in multiple colors and resembling tumbled river stone. This a great stone topping for fire pits that add a contemporary look. But if you prefer the rugged look of natural fire pit lava rocks, there are a variety of shapes, sizes and colors to choose from.
What are Lava Rocks?
The name “lava rock” is a little misunderstood. It is actually called volcanic rock and is formed from lava as it is cooled. Depending on how fast the lava cools determines what characteristics the rock will have. If the lava cools very quickly, it creates a black glassy substance called obsidian. When filled with bubbles of gas, the lava may form the spongy appearing pumice. Allowed to cool slowly, it forms a light-colored, uniformly solid rock called rhyolite. For fire pits, the typical lava rock looks like pumice, very porous but more jagged, made of basalt and is generally gray to black in color, though red is a popular color as well.
Benefits of Using Lava Rocks
One of the main benefits of using lava rocks versus any other type of fire pit medium is cost. Pound for pound, lava rocks cost less to fill the same area than say fire glass because they are both lighter and don’t require the manufacturing process of fire glass. 100 pounds of 1″ lava rock goes for around $200 whereas fire glass of equal weight and size goes for around $300. Lava rock is very durable as well, can withstand high heat, and doesn’t generally discolor over time. The rock also retains heat slightly better than ceramic fire logs and can be arranged in more configurations than ceramic logs.
Lava rock can also be used as a filler too. If you have a deep fire pit, you can fill it up to the burner level with inexpensive pea-sized lava rock and then use the larger sizes to finish off the overall look. Lava rock can even be used purely for decorative purposes too. For example, your fire pit may have fire glass in the middle and a ring of red lava rock surrounding it. Depending on how the rock is arranged affects the flame color too. Since lava rock is very porous and the fact that there is alot of air space between lava rock when mounded, you can achieve a beautiful bright yellow flame because of the extra oxygen available to the burner.
Types of Lava Rocks
Lava rock for fire pits come in many shapes, sizes and colors. The smallest of sizes, from 1/2 to 1 inch in size, are generally used to fill the fire bowl area and hide the burner. You can mound up lava rock with different sizes too by placing lava boulders of 3 to 6 inches in size on top of small lava rock. This forces the fire to go through the cracks and crevices of the bigger rock providing the appearance of a larger, more active fire. And bedding the fire pit with lava rock in this manner tends to retain overall heat in the pit more effectively than other materials, such as a mound of ceramic logs.
Lava rock also comes in a less traditional rounded or rolled shape, similar to that of river or beach rock. The rocks are about 1 to 2 inches in size, comes in multiple colors and can be piled into the fire bowl in the same manner as traditional lava rock. Or you can create a decorative ring of smooth lava rock around the outside of the fire bowl to compliment naturally rough lava rocks, providing a unique and personal design.
To figure out how much it would cost to convert to or add lava rocks to your current fire pit, you must determine how much you need. Measure your fire pit’s dimensions so you can calculate the amount of rock necessary. If math isn’t your talent, you can try calling lava rock retailers to see if they can give you a hand. There are also online calculators that you can punch in the dimensions of your fire pit and the calculator will determine your needs depending on the size and shape of the lava rock you choose.
For the courageous type, you can calculate the amount needed by finding the size of your fire pit in square inches and multiplying that number by 3 or 4, which is the amount in inches needed to have a good base of lava rock for the fire to radiate through. Give this final number when buying so the retailer can determine how many pounds of rock are needed as lava rock is typically sold by the pound in bulk.
Price ranges by the pound are typically $2 for small 1/2 inch to 1 inch in size to upwards of $5-10 for large lava boulders. So if you have a square fire pit that is 24″ x 24″ and want 4″ of lava rock depth, you would need about 60 pounds of small to medium sized rock. Multiply that by $2 and you can convert your fire pit to rugged lava rock for under $120.
Rock Your Fire Pit
Just because you bought your fire pit with boring ceramic logs doesn’t mean you have to stick to them. If you want a rugged look where the flames dance in and out of the rocks, dress up your fire pit with big lava boulders. Use smaller fire pit lava rocks as filler to hide the gas burner and top it with rolled lava stones for a contemporary appearance. Whatever the look you desire, decorative toppings such as lava rocks are sure to provide a safe, clean, inexpensive and durable fire medium for years to come.