How to Convert a Gas Grill to Lava Rocks

Co-authored by wikiHow Staff

Last Updated: May 10, 2020 References

If your gas grill doesn’t heat up like it used to, or you just want a change, lava rocks make a great addition. You’ll still use the gas to heat the grill, but the lava rocks store the heat better and distribute it throughout the grill more evenly. All you have to do is take out the burner guard and install a new grate for the rocks. Lay them out evenly and see how much they improve your grilling!

Part 1

Part 1 of 3:

Taking Apart the Grill

1
Take out the grill grate. It's important to clean the grill before you add lava rocks. Take the main grate you cook on out of the grill. You need it out of the way so you can add the rocks. Now is a great time to give the grate a good cleaning if you don’t clean it often. Set the grate off to the side of the grill for now.^{[1]
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2
Remove the heat tent from over the burner. Most gas grills have a metal shield that covers the burners from grease drippings. Your grill may have one heat tent that runs across the grill, or there may be more than one. Remove them all if there are more than one.^{[2]
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- For the lava rocks set up, you’ll not be putting the heat tent back into the grill. Store it somewhere you’ll remember it in case you want to put it back on at another time.
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3
Clean the bottom of the grill chamber. While your grill is more empty than usual, give the bottom and the sides a good scrub. You might use hot, soapy water, or degreaser for heavier buildup. Wipe the burners and the bottom of the grill until they are clean.^{[3]
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Part 2

Part 2 of 3:

Installing the Lava Rocks

1
Buy lava rocks. Visit your local home improvement store, garden store, or big-box store, like Walmart. Look for lava rocks in the landscaping or garden section. Get rocks that are at least a couple square inches (roughly 5 sq. cm) so that they are big enough to sit on a grate.
- Stores might sell lava rocks by the pound or in a package. Make sure you get enough to create a single layer across the entire length and width of your grill.
2
Lay a new grate over the burner. Buy either a tray that is specifically made for lava rocks or another generic grate similar to the one already in your grill. Make sure it is small enough to fit into the lower part of the grill, but large enough to reach all sides of the grill.^{[4]
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- A cookie cooling rack might serve the purpose perfectly.
3
Add lava rocks in a tightly packed layer. Line the grate with lava rocks from side to side in all directions. Place the rocks close together so they are touching, but don’t pack them so tight that they are overlapping or piled higher than one layer. Arrange the various shapes and sizes of rocks so they fit together.^{[5]
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- If the rocks seem pretty dusty, rinse them off with water before you put them into your grill. Dust won't necessarily harm anything, but they may not heat up as well if they're dirty.
4
Place the grill grate back into the grill. With the lava rocks installed, insert the cooking grate back into its position. The grilling grate should be high enough that it leaves room between it and the lava rocks below it.
- If you’ve never taken the grate out before, double check that you’ve put it back in correctly.

Part 3

Part 3 of 3:

Maintaining Your Lava Rocks

1
Turn your lava rocks over periodically. As you cook on your grill, grease drips onto the lava rocks. Since they are porous, some grease will soak in over time. To avoid heavy buildup on one side of the lava rocks, flip them over every month or two, depending on how often you use the grill.^{[6]
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- If you use the grill daily, you’ll want to flip them every two weeks. If you use the grill once a month, you probably don’t need to flip them until six months after you install them.
2
Clean the lava rocks after about six months. Clean your rocks if they become obviously dirty but you don’t want to replace them. Remove them from the grill, and soak them in hot water with dish soap for about one hour. Then let them soak in clean, cold water for another hour.^{[7]
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- Grease won't dissolve in water, so the addition of dish soap is important. Even so, you won't completely remove all of the grease from the rocks.
3
Replace your lava rocks every year or two. The lava rocks that you install now are not meant to be permanent. They will need to be changed on occasion. Use your best judgment based on how often you cook on the grill.^{[8]
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- If you use it every week, replace the rocks yearly. If you only use it a half dozen times a year, leave the rocks in for two years.

Community Q&A

Question

How do I light lava rocks in a gas grill?

Community Answer

Does the grill have a separate compartment for wood smoke? You could wrap them in foil and carefully add tinder or a charcoal briquette to it and wait for the rocks to alight. If no separate compartment, put the foil on the side of the burner, under the grates.
Question

Do I lay the lava rock tray directly on the gas burner, or does there need to be a space between burner and the tray?

Community Answer

You do need a small amount of space, enough for oxygen to do its thing and circulate. Place the rocks in foil, set them down by the burner--not on top of it--and light a small briquette to start the process.
Question

Do lava rocks help prevent flareups?

Community Answer

They do, unless some small piece of grease or fat drips on them directly. Consider having a small wire mesh that could entrap that fat/grease.