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What Are Gas Fireplace Logs Made Of?

Gas fireplace logs are primarily made of either refractory ceramic, ceramic fibers, or refractory cement. They are designed to resemble real wood, and they also happen to be fire-resistant. To make the logs look as realistic as possible, they are made using actual wood molds.

These logs are also designed to last for years, with most of them not needing replacing for 2 to 5 years. Gas fireplace logs can also be installed in traditional wood fireplaces.

All three types of gas fireplace logs are designed to be as realistic looking as possible. However, subtle differences play a role in determining the kind of gas logs right for you.

Ceramic Fiber Logs

When it comes to buying gas logs, ceramic fiber logs are usually cheaper than the rest. 

Compared to other logs, they are light in weight. However, one downside is that sometimes they tend to give out an unpleasant odor when being used. 

Refractory Cement Logs

These logs are made from a mixture of cement. Because of that, quality ranges from one manufacturer to another, with both cheap and very expensive options being available. 

The difference? The high-quality logs tend to look realistic if you are going for that authentic traditional wood-looking fireplace. 

Since these logs are made of cement, they are likely to crack over time—especially when exposed to high temperatures. 

This means that they are not as long-lasting as you would want your gas logs to last. 

Refractory Ceramic Gas Logs

Ceramic gas logs are made from mixing ceramic and cement. Such logs tend to give off more heat than ceramic fiber and refractory cement logs. 

They also last longer mainly because the material can withstand even the highest of temperatures without cracking. These logs can be in either vented or ventless fireplaces. 

The only thing you need to prepare for if you purchase these logs is the change in color over time. Before that happens, however, you can be sure that they will have served you for a long time. 

One thing that is common with all types of gas logs is that they are mostly for aesthetic appeal rather than for warmth. 

They, however, do emit heat but not in the same intensity as traditional built-in gas fireplaces. Most of the heat generated, just like with a wood-burning fireplace, goes up the chimney. 

At the end of the day, however, they are cheaper in the long run when compared to using a wood-burning fireplace. 

When choosing the gas logs for your fireplace, you might want to consider the styles of gas logs that exist. Gas logs fall under two categories: vented and ventless gas logs. 

Types of Gas Logs

Vented Gas Logs

These gas logs are designed to be used in a traditional wood-burning fireplace that has a fully functioning chimney. Such logs serve as a great replacement for wood logs. 

They feature realistic detailing meant to resemble real wood logs. They also produce golden flames like the ones produced by a wood fire. 

Vented gas logs cannot be used where there is no operational chimney. The chimney damper also needs to stay open every time.

If the damper is not kept open, it could lead to a buildup of carbon monoxide. Such logs are not the most efficient heat sources if you are buying them for warming purposes.

Since the chimney damper stays open, most of the heat the logs produce is lost through the chimney. 

Ventless Gas Logs

As the name suggests, such gas logs don’t require a functioning chimney with them. They are designed to produce smokeless and clean flames. They burn well since there are no harmful combustion gases produced in the end. 

The flames produced are smaller and tend to be blue in color. While the logs can still give the illusion of a realistic fireplace, the flames are not large enough or as authentic as those produced by vented gas logs. 

When ventless gas logs combust, no air escapes through the chimney. Because of that, such logs tend to give off an odor when they are burning, which enhances other odors that may already be present. 

If you, therefore, use such things as scented candles or air fresheners, ventless gas logs will strongly enhance the odors.  

Are Gas Fireplace Logs Toxic? 

Gas logs, like wood logs, have the potential of producing harmful combustion gases like carbon monoxide. Vented gas logs rely on a type of exhaust system to function, while ventless gas logs don’t require such a system. The fireplace and the venting system are what determine the level of CO that remains inside the house. 

Ventless gas logs are designed to burn to nearly 100% combustion producing very hot flames. Such that, this ends up lowering the levels of CO as well as soot that is produced. 

Such gas logs come with some sort of Oxygen Depletion Sensor (ODS) that works by turning off the gas before the levels of CO reach a life-threatening level. 

Vented gas logs, on the other hand, produce CO, which is why they need to be used with a functional chimney with the damper open at all times. 

Regardless of the gas logs you are using, you are better off installing carbon monoxide detectors around the house. 

Sure, they don’t come cheap, but you can rest easy knowing that there is no risk of carbon monoxide reaching dangerously high levels without knowing. 

How Long Do Gas Fireplace Logs Last?

There is no set timeline on how long you can use your gas logs before they need replacing. The truth is, so many factors affect this timeline. Ideally, the lifespan of your gas logs will depend on the usage frequency and the material of the logs. 

Some gas logs are made of cement. Such gas logs, depending on how often they are used, will begin fading over time. Most of them will need to be replaced after every 2 to 3 years. 

However, most modern gas logs are made of ceramic. Ceramic is durable and able to withstand extreme heat, therefore likely to last long.

If you have a vented fireplace that is well maintained and uses ceramic gas logs, you can expect your log sets to last for even 10 years. The same kind of logs used in a ventless fireplace will have a lifespan of between 3 to 5 years. 

These are just estimates, though, and the lifespan of your logs will still depend on how often they are used. And that begs the question: how do you know that your gas logs need replacing? 

After some time, gas logs tend to change in appearance, which is what you need to look out for. If your gas logs start fading or there is just general wear and tear like a crack here or a crumble there, it’s a clear sign that you need to think about buying new logs. 

Generally, you should expect your gas logs to last several years. Of course, the higher the quality of your gas logs, the more the lifespan. 

So, when you are buying gas logs, therefore, while you may want to spend as little as you can, go for the highest quality. 

Need More Help?

You can always ask us here at Fireplace Tips, but you should know the other resources available to you! Here are the resources we recommend.

  • Chimney Safety Institute of North America (CSIA): The CSIA is your BEST resource for fireplace and chimney safety at home. They’re a non-profit governed by a volunteer board of directors dedicated to the education, training, and certification of chimney and industry related professionals.
  • Self-Sufficiency and Off-Grid: If you’re like me and passionate about off-grid and self-sufficiency, see my number 1 resource—Abundance Plus. Check out their Frugal Homesteading Course on growing 90% of your own food. Get 7-days free and 10% off with the code: TYLER10