If you’re looking to liven up your outdoor fire pit or fireplace, fire glass is a fantastic choice. Its shimmery, sparkling look and vibrant selection of colors are a refreshing option over the usual brown, “blah” lava rocks and stones. You’ll love the way the fire appears to skip and dance across the glass—it’s a mesmerizing show! But even in the light of day, when your fire feature is dormant, fire glass provides dazzling beauty all on its own.

While you may be tempted to fill your cart with fire glass right away, it’s a good idea to learn all you can about this fabulous fire pit media before you buy. That way, you can be sure you’re getting the right product in the right amount and using it properly. The results—a showstopping fire feature that enhances your home’s outdoor living space—will be worth the wait!

Here are some common questions and answers to help “fuel” a smart fire glass shopping experience.

1. Is fire glass really safe to use in my fire pit?

Fire pit glass is a special type of decorative glass that’s used to beautify outdoor gas fire pits and fireplaces. It comes in a variety of types including tempered fire glass, crushed fire glass, fire glass diamonds and fire beads.

But wait a minute. Using glass in your fire pit—is that really safe?

Absolutely! Fire glass isn’t made of regular glass, like the type your drinking glasses are made of. It’s constructed of specially manufactured heat resistant glass that’s inert – meaning it doesn’t contain any finishes, additives or combustibles. Its color is achieved by adding metal oxides or metal powders to the glass in order to change its shade.

Fire glass is highly heat-resistant, making it perfectly suitable for use in an indoor gas fireplace or outdoor fire pit or fireplace. Unlike traditional glass, it won’t burn, melt, disintegrate or explode. It also won’t easily fade or turn odd colors. And, even more importantly, fire glass will not produce toxic or bad-smelling fumes when it’s burnt. This is a big consideration—especially if you have small children or animals at home. After all, who wants to breathe in dangerous chemicals when they’re trying to enjoy a relaxing evening by the fire?

2. Do I need a special kind of fireplace to use fire glass?

You can use fire glass in virtually any propane or natural gas fire feature. You can’t, however, use it in a real wood-burning fireplace. When using fire glass in a gas fireplace, you can simply replace the lava rocks in the bed of your fireplace with fire glass to add extra sparkle or some color. If your gas fireplace has a “burning embers” look achieved by running gas through a non-combustible material (usually vermiculite), you cannot replace this artificial material with fire glass.

3. Do I need glass doors or screens on my fire feature when I use fire glass?

It’s not necessary to use glass doors and spark screens with fire glass, since this media does not throw hot, popping cinders when burned. However, you may want to consider safety barriers if you have small children or nosy pets in your home.

4. Should I cover the burner with fire glass, or should I leave it exposed?

Yes, you should cover the burner — but only with just enough fire glass so that it’s not visible. This is especially true if you’re using a propane fire feature, since propane is heavier than air and needs to be dispersed close to the flame. Natural gas is lighter than air, so it will rise to the surface on its own – as such the fire glass can cover the burner to a deeper depth.

To be honest, this is the most common mistake we see in fire pit installations. The builder constructs a gorgeous fire pit, but leaves the burner rings exposed! The rings really are an unsightly eyesore, sitting there right in the middle of a bed of beautiful fire glass. Don’t make this same mistake with your own fire feature-be sure to provide enough coverage to conceal your burner. Trust us, it makes a huge difference!

5. How deep should the fire glass be?

Ideally, your fire pit should be filled with fire glass to a depth of 1” to 2”. You want to have enough fire glass so that your burner isn’t visible. On the flip side, creating a layer that’s more than 2” deep is unnecessary—and quite frankly, a waste of money. (Note: If you have a depth greater than 2” to fill, take a look at the “Can I use my existing lava rocks as a filler under my fire glass?” question below.)

6. How much fire glass do I need?

First of all, we always recommend you purchase less fire glass than you think you need—then add more fire glass as required. Why do we suggest this? Well, with the fast and free delivery offered by manufacturers like Celestial Fire Glass, it’s much easier to order an additional jar than it is to ship an extra jar back (when you consider the hassle of repackaging, adding a label and driving the package to your local UPS drop-off location).

Now, to help you determine how much fire glass you need, we’ve created an easy-to-use fire glass calculator. Simply enter the size and depth you want to fill, and the calculator will determine how much fire glass you need to buy. Here’s a tip: round down to the nearest 10 pounds, and then add more glass in a second order if needed. See our handy fire glass calculator to determine how much you need.

7. Can I use my existing lava rocks as a filler under my fire glass?

Most definitely, YES! By serving as a filler, lava rocks are a convenient, cost-effective way to reduce the amount of fire glass you need to buy. This is a hugely helpful money-saver if you’re the owner of a large or deep fire pit. As long as you have 1” to 2” of fire glass over your lava rocks, and the lava rocks are no longer visible, you’re golden. If you don’t have lava rocks and you have a large and deep fire pit to fill, try purchasing some pebble stones from your local Home Depot or Lowe’s. These make a great filler at a low cost.

8. What type of fire glass should I buy?

The answer to this depends on what look you’re trying to achieve for your outdoor fire feature. There is no best fire glass, rather it’s a design choice. Do you want to add some glam and glitter? If so, go with the 1/2” reflective tempered fire glass. The reflective backing and smooth finish on the glass will give you the most luster and sparkle possible. Plus, the 1/2” reflective tempered fire glass is the most popular of all fire glass types, so you can’t go wrong with this choice.

If you prefer less flash, but still want some reflective accents to add visual interest to your fire feature, we recommend the crushed fire glass (1/2” to 3/4″). Crushed fire glass will allow you to infuse your fire feature with some lovely color, which will reflect some of the flamelight on nice gravel-shaped fire glass pieces.

Another thing to consider when choosing your fire glass is that tempered fire glass may have some sharp edges. Why? While tumbling is a common safety measure with many brands of fire glass, tumbling actually dulls the surface of the glass (creating a “frosted” look) and causes it to lose some of its reflectivity. That means, to ensure maximum luster, you want to choose tempered fire glass, which isn’t tumbled. Un-tumbled, tempered fire glass provides a stunning amount of light reflection and will definitely take your fire feature to a new aesthetic level. But given its sharp edges, tempered fire glass may not be the best choice in homes with small children. If you do use it, take care to keep the ground free of stray pieces so that no one steps on them.

If you’re searching for a fire glass variety with fewer sharp edges, try crushed fire glass, whose pieces have a natural, gravel-like shape. Fire glass diamonds are also another great choice. Featuring a zircon shape with rounded edges, this type of fire glass delivers incomparable radiance with an added measure of safety for your peace of mind. It eliminates the traditional sharp edges that can be worrisome around small kids and household pets.

9. What color fire glass should I buy?

Fire glass color is very subjective, depending upon your personal preferences, your outdoor / backyard décor (e.g. style and color of your patio furniture) and the mood and feel you’re trying to achieve in your backyard space. Lighter colors offer superior luminosity and evoke an elegant, chic feel. Earthy colors provide a warm, rustic look (think cozy autumn evenings!). Rich, deep or vibrant colors can lend a contemporary feel to your fire feature. We did a bit deeper into what’s the best fire glass color in our article What Color Fire Glass Should I Use.

Here’s some color guidance to get your wheels turning:

There are many exciting colors to choose from, which is why fire glass is so popular. The four colors recommended here are top customer favorites—as well as ours!

Know what else is awesome? You can get creative and mix different colors of fire glass to create your own unique look, whether you want to blend two shades or four. What’s more, you can change your fire glass shades with the season. For example: Sunstorm Gold for fall, Diamond Starlight for winter, Neptune Blue for spring and Tropical Blue for summer. Fire glass from Celestial Fire Glass which comes in plastic jugs (versus flimsy plastic bags that break spill) is easy to store.

Fun fact: If you find you have some fire glass left over after filling your fire pit, try using it to add a splash of color and shimmer to your water feature or in decorative vases and bowls.

Here are a few of our favorite colors of fire glass:

Need some inspiration? Check out our Gallery of Projects and prepare to be astounded!

10. Will the fire glass require a lot of cleaning and maintenance?

That’s one of the wonderful things about fire glass: it’s relatively maintenance-free if properly cared for. If it’s used in an indoor gas fireplace, there really isn’t any cleaning or maintenance required. You get all the beauty, without the work!

If fire glass is used outdoors, maintenance depends on many factors. First, there are three common things that cause outdoor fire glass to become dirty: bird droppings, leaves and other types of natural debris and improper air mixture in propane gas. The first two of these depend on where you’re located; for example, in upstate New York you’re more likely to be affected by falling leaves, bird droppings and acorns than in Arizona. If you’re in an area with a lot of birds and trees, we recommend putting a stainless-steel cover over your fire pit when it’s not in use. This simple move will keep your glass free of bird droppings and leaves, pine needles, etc. and save you loads of time (and headaches).

The third cause, improper air mixture with propane gas, can be fixed in several ways. In fact, we have an article to help you troubleshoot and fix this problem.

If you ever do need to clean your fire glass, don’t despair. It’s easy to clean any type of fire glass using items you probably already have around your house—and it comes out looking sparkling-clean and brand new. See detailed cleaning instructions here.

11. I rent my home. Can I take my fire glass with me when I move out?

Yes! It’s easy to scoop out fire glass from one fire pit and place it in another one—especially if your fire glass came in a sturdy plastic jug (great for storage and transport).

Congratulations! If you made it to the end of this article, you’ve graduated from Fire Glass 101. Now you’re ready to start shopping to create the backyard fire pit of your dreams.

Other resources you may be interested in:

• What Color Fire Glass Should I Use?

  Which color fire glass do you like best? It’s really that simple. All of the Celestial Fire Glass options are beautiful in their own right, so it’s really just a question of, “What speaks to you?”  If you already have…

• Lava Rock or Fire Glass - Which is Better?

  There is no definitive answer to this question. The more important question is, which suits your home design and lifestyle better---lava rock or fire glass? A $12 million mansion demands the razzle and dazzle of fire glass. Whereas fire glass…

• What is Fire Glass?

  Fire glass is a special type of decorative glass that's added to outdoor gas fire pits and fireplaces to enhance their beauty. In a gas fire pit, fire glass conveniently keeps the burner out of sight; only the decorative glass…