How to Arrange Gas Logs

Burning gas logs in a fireplace has some advantages over burning wood. Gas logs are less messy, and you won't need to stockpile wood, yet these logs can give off that cozy look and feel of a wood-burning fireplace. But if you want your gas fireplace logs to look real, you should choose them with care.

Burning Logs and Glowing Embers In Gas Fireplace
credit: ryasick/E+/GettyImages
How to Arrange Gas Logs

Gas Fireplace Setup

You want your gas log configuration to be done in a way that resembles a wood-burning fire. You also want those logs to be arranged safely.

Start with good-looking, vented gas logs. There are realistic looking logs, even with embers that look charred. Gas logs are often made of heavy or light ceramic material, even though they look like wood.

Use high-quality gas logs that resemble the cut firewood you see in a wood-burning fireplace. Also, look for realistic-looking twigs and branches in your log set. Measure the logs to make sure they're the right size for your fireplace opening. Make sure your fireplace opening still has plenty of room around the logs.

Size Your Logs Right

Don't assume your fireplace should look chock full of logs. It shouldn't. Measure your fireplace before you buy your log set, and make sure you have 12 to 20 inches of clearance above and 6 to 18 inches of extra space on either side of your log set. Also, consider the size of your burner and grate when measuring.

Gas Fireplace Log Placement

Before you arrange the logs, turn off the fire and turn off the gas source. This may also be a good time to clean the firebox or have it cleaned by a professional. Then follow these steps:

  • Make sure the gas line is properly attached to the gas burner.
  • If you have a remote start, plug the receiver into the remote box.
  • You'll need pipe thread sealant, adjustable wrenches and screwdrivers to set the logs. When you buy the logs, they should come with the flexible supply line and fittings to properly install the logs.
  • Place the logs according to the manufacturer's directions. Typically, the largest logs go on the bottom. Arrange smaller logs over these, making sure that the gas source has plenty of airflow around it. Many kits provide specific directions as to how to fit the logs together so you end up with a natural-looking set of stacked logs.
  • Make sure the burner is covered with sand or vermiculite and embers that either come with your burner or are designed to go with your burner.
  • You can also add in little rocks that look like coals to give your fireplace that burning-ember look, along with accessories that look like partially burned wood. These noncombustible materials can be arranged around the base of the logs to make your fire look real.
  • You may even have pieces of rock wool that look like glowing hot coals. You can also spread lava rock around the burner to add to the look of the hot embers.

Make Adjustments

You may need to adjust your gas fireplace log placement after you've arranged the logs. If you realize the flame is burning some of the logs directly, it's not an immediate safety issue, but you may want to rearrange the logs to prevent soot buildup on them. Your logs won't last as long if soot builds up.

Types of Fireplaces

Do you have a fireplace that burns gas logs or do you have a gas fireplace insert? If you have an existing fireplace opening, you can burn gas logs in this. It's perfectly OK to buy a set of gas fireplace replacement logs for a wood burning fireplace as long as you have a gas line that runs to your fireplace.

If not, you can have a professional run a gas line to your fireplace. Gas log sets are often sold pre-arranged. You can buy individual logs, although some manufacturers recommend you buy gas logs in sets only.

If you have a gas-only fireplace, not a wood-burning fireplace, these usually come in sets, with the logs already arranged. If your fireplace is gas only, which means it was not meant to burn wood, you probably shouldn't be buying a new set of logs and connecting them to a gas line yourself. This job is likely meant for a professional.

A Word of Caution

Don't buy gas logs meant for a wood-burning fireplace with a gas line and then use them in a fully enclosed gas fireplace. A fully enclosed gas fireplace can't handle the heat generated by these logs, and burning such logs could pose a fire threat.

If you aren't sure whether your fireplace is wood burning or gas only, wood-burning fireplaces normally have a damper and a flue liner or a metal box with a round metal chimney pipe that's at least 8 inches in diameter. If you're still not sure, consult a professional chimney expert or gas expert.

Vented Gas Logs

The term gas logs is a bit of a misnomer. The logs themselves aren't made of gas. Vented gas logs are designed to burn using gas as the fuel source. These are the logs you're most likely using for your fireplace. Of course, they're not made of wood. Typically, they're made of ceramic refractory, which is like concrete, or ceramic fiber, which is lighter in weight.

Ceramic refractory logs are durable and rarely shift. They may accumulate soot, however, and they don't glow. Ceramic fiber logs are better at resisting flame damage and some glow when heated. But they do break down with age, and they don't look quite as realistic.

You can buy vented logs for gas fires and burn those in any fireplace that's designed to burn wood, as long as it has a gas line. You can also use them in outdoor fire pits that are designed for gas logs, although not all vented fireplace logs are meant to be used outdoors.

Ventless Gas Logs

There are also ventless logs for wood-burning fireplaces. If you're using ventless logs in your wood-burning fireplace, you'll want to burn these in a fireplace with the flue closed or in an approved ventless firebox that's rated for logs from an aftermarket source.

Ventless logs require a little more care because without a venting source, you want to make sure the fumes don't accumulate in the room. When not vented properly, natural and propane gas can cause carbon monoxide to build up.

You should buy a set of ventless logs certified by Underwriters Laboratories, a nonprofit organization that tests products for safety. UL certifies logs based on the way the logs are arranged when they're sold.

The Trouble With Ventless

Ventless ceramic logs don't always stay in place, however. Many gas log manufacturers recommend if that happens, especially with ventless logs, to call a professional to rearrange them properly, using UL standards and the manufacturer's recommendations.

Ventless gas logs aren't legal everywhere, including all of California. Many counties and municipalities in other states prohibit them.

Additions to Your Logs

There are some ways to make your gas log fire look more realistic. Rock wool embers and lava rocks help. Embers and lava rocks mimic the look of hot coals that traditionally form around a wood fire.

You can also add other items designed to look like wood chunks, acorns, pine cones and more. There are lots of accessories available, limited only by the size of your fireplace and your imagination. Some choices include tempered glass chips and, for a rustic feel, colored ceramic rocks.

Burners and Grates

You can use a sand or vermiculite pan burner system, which uses silica sand or vermiculite to diffuse fuel gas and creates a realistic looking flame pattern. Other burners may use a pan filled with ceramic pebbles to create realistic looking flames. Tube burners typically have flames that are more static and less realistic looking.

Many burners come with log grates that are sized to the burner but look like a traditional fireplace log grate.

Soot on Your Logs

If your gas logs get soot on them, you might need to examine the instructions that come with your burner. Depending on whether you use natural gas or propane, which comes in through tanks that are installed outside your home, you may not have enough material covering your burner.

Propane is heavier than natural gas and uses vermiculite, not sand, around the burner.

Gas Log Burners

You should also make sure you have a gas log burner for your wood-burning fireplace when you buy new gas logs. Some wood-burning fireplaces have log lighters. These aren't meant for gas logs. These are meant to be used to start a wood-burning fire without kindling.

That doesn't mean log lighters won't work with gas logs, but using gas logs with a log lighter is another major cause of soot on gas logs. This is happening because the fuel/air mixture isn't being controlled properly. This soot can also spread outside the fireplace onto your walls and furniture.

So to prevent unnecessary problems, make sure you use a burner that's meant to work with gas logs.

Some Safety Tips

  • You should still have your chimney inspected if you burn gas. The gas produces smoke and can produce soot inside your chimney. You also want to make sure no animals are using your chimney to nest and that there are no cracks or leaks, which could allow gas to leak into your home. It's a good idea to do this annually.
  • Install a carbon monoxide detector in the room where your gas-burning logs are used. You want to make sure there's no carbon monoxide leaking in your home. This odorless, colorless gas can cause poisoning and even be fatal.
  • Never burn your gas logs with glass doors closed on your fireplace. This will cause the burner to produce too much soot and carbon monoxide. This can also cause components in your gas valve to melt and potentially explode.
  • If you're burning ventless logs, even when used properly, make sure to open your window a crack after an hour or so to let in some fresh oxygen.

Wood Stoves

Never install gas logs in a stove meant to burn wood. A wood stove is a closed system, and gas logs will heat up and possibly explode. Wood stoves are designed to use much less air than a fireplace. They usually have a smaller vent than a fireplace, which means it won't be enough to vent the fumes that gas logs give off.

Efficiency of Gas Logs

Vented gas log fireplaces are more efficient than wood-burning fires. Fully enclosed gas fireplaces are more efficient than those built into existing fireplaces, but even an existing fireplace retrofitted to support gas logs will fill your room with warm air and radiant heat. Not only are they easy to light, but you can start and stop a fire almost instantly.

Lifespan of Gas Logs

A properly installed gas log set should provide you with 20 years of use, especially if you have refractory ceramic logs. Your annual chimney inspections will go a long way toward helping you get the most life out of your gas log set.


Karen Gardner

Karen Gardner

Karen Gardner spent many years as a home and garden writer and editor who is now a freelance writer. As the owner of an updated older home, she jumps at the chance to write about the fun and not-so-fun parts of home repair and home upkeep. She also enjoys spending time in her garden, each year resolving not to let the weeds overtake them. She keeps reminding herself that gardening is a process, not an outcome.