What To Do if Your Fireplace Cracks (4 Fixes)

There’s nothing quite like lighting a fire on a cold evening and feeling the heat radiate across the room. Although lighting a fire in a fireplace can be a relaxing and enjoyable experience, it can become dangerous if you notice any cracks. So, what should you do if your fireplace cracks? 

The right approach to fixing a crack in your fireplace will depend on how big it is. Here are the most common fixes: 

  1. Cover the cracks with fire cement if they’re small. 
  2. Replace the panel(s) if the cracks are large. 
  3. Hire a professional to examine the fireplace. 
  4. Fill the mortar joints with mortar if they’re cracked. 

This article will discuss these common fixes in greater detail, so be sure to keep reading to find out more. 

1. Cover the Cracks With Fire Cement if They’re Small

You may have noticed some small, thin cracks around the walls or bottom part of your fireplace. In most cases, these cracks can easily be covered and fixed, DIY-style. 

These cracks are generally not as dangerous as larger cracks, but you should deal with them promptly to prevent the cracks from expanding. 

You’ll only need a few things to cover the cracks in your fireplace: 

  • Fire cement. You can buy cement that needs to be mixed, or you can purchase pre-mixed cement. Meeco’s Red Devil Refractory Cement on Amazon is an excellent choice if you want something that you can use right away. 
  • A spatula. Any metal cement spatula will be fine for this method. 
  • A brush (and vacuum if possible). You’ll need a dustpan and brush to sweep up dust. 
  • Damp cloth. You’ll need a damp cloth to wipe away any remaining dirt. 

Once you’ve got everything you need, you’re ready to go! Now, let’s take a look at a step-by-step guide on how you can cover these minor cracks. 

Remove Everything From the Fireplace

Before you start filling in the cracks, you’ll need to make sure you remove everything from the firebox. If you’ve got any stands inside, take them out. 

Once the area is clear, you can move on to the next step.

Clean Out the Fireplace

Cleaning the fireplace is essential if you want this process to work well. If you don’t sweep up all the dust and other dirt, it may affect the cement later. The first thing you should do is sweep up as much dust and debris as you can. 

Once you’ve done that, you should use a vacuum if you have one; this will ensure you get rid of any extra dust that may be hard to pick up with a dustpan. 

Next, you’ll need a damp cloth to wipe the fireplace; this helps eliminate any remaining dirt leftover. After this, your fireplace should be ready for the next step. 

Fill the Cracks

Filling the cracks is super easy; all you need to do is grab your spatula, dip it in your fire cement, and start spreading it over the cracks. Make sure you distribute it evenly over the surface. 

You can choose to cover the cracks alone or cover the whole area to make it look more uniform; this isn’t necessary, so it’s up to you to decide. You could choose to cover the cracks and then paint the whole inside of the firebox to give it a more aesthetically-pleasing finish. Again, it’s up to you how you want it to look. 

Remember that some fire cement requires you to mix it with water before using it, so make sure you read the instructions before beginning this step. 

Let It Dry

The amount of time you’ll need to let it dry depends on the product you used. You should check the packaging to check how long it takes to dry. Some types of cement only take a few hours, whereas others may take days, weeks, or even months. 

Meeco’s Red Devil Refractory Cement (available on Amazon), for example, only takes up to two hours to dry. Once the cement has dried, you can light a fire as usual. 

2. Replace the Panel(s) if the Cracks Are Large

A few small cracks here and there is a simple problem to fix, but if there are many large cracks in a panel or even just one large crack, it’ll be easier and safer to replace the panel altogether. 

The National Fire Protection Association (NFPA) recommends removing any panels that consist of large cracks because they can no longer safely contain the fire and pose a general health and safety risk to the people in the household. 

The panels are the walls of the fireplace. There is usually one at the back and two on both sides. If you’re replacing the back panel, you’ll likely need to remove the side panels first. 

If you don’t have experience with fireplace maintenance, you should hire a professional for this. However, you should have no issues doing it yourself if you have experience. 

Before you begin this process, you should clean your fireplace to avoid excess dust getting in the way. Dust is unhealthy to inhale and gets in the way when removing panels. 

Below is a step-by-step guide on how to replace fireplace panels: 

Buy a Replacement Panel(s)

You’ll need to know the measurements of the old panel so that the new one will fit correctly in the fireplace. You can order a replacement panel from a store specializing in fireplaces, and you should give them the correct measurements. 

Most chimney sweeps will order a large panel and then cut it down to the correct size when they receive it. 

If you don’t feel comfortable measuring and ordering the panels yourself, you can hire a professional or get someone more experienced to help you. The panels must be the correct size. Otherwise, they won’t fit. 

Remove the Panel(s)

Once you’ve got your replacement panel(s), you’re ready to get started. If you’re replacing all the panels, you should remove them by beginning with the side panels. Then, you can remove the back panel. 

There are usually clips or screws that keep the panels in place. Make sure you keep these because you’ll need them when installing the new panels. 

If you’re only replacing a side panel, remove the panel you want to replace. If you’re replacing the back panel, you’ll need to remove both side panels first. You can put them back in once you have replaced the rear panel. 

You must be gentle while handling the panels because they’re fragile. Additionally, it’s a good idea to wear protective work gloves when handling fireplace panels. They can be sharp and give you cuts if you’re not careful. 

Put In the New Panel(s)

Once you have removed everything, you’re ready for the next step! As I mentioned earlier, these panels are often very fragile, so you want to make sure you don’t break or mishandle them. 

If you’re replacing all the panels, you can start by putting the back panel in first, followed by the side panels. 

If you’re only replacing the back panel, you can place the new panel right in. Then, you can put the two old side panels back in their place. Use the clips or screws to put them back in place. 

I would also recommend watching a video to understand the process better. You should watch the video below to learn more about installing replacement fireplace panels: 

3. Hire a Professional To Examine the Fireplace

If there are a lot of cracks or if you don’t have a lot of knowledge on fireplaces in general, you should call a professional. Since significant gaps are often dangerous and even life-threatening, it’s essential to have some expert eyes look at the fireplace. 

If you hire a chimney professional, they’ll also be able to examine the chimney in case there are more cracks there. If it ends up being something easy to fix, the professional can tell you what you need to do or offer to do it for you. 

Even if it ends up being something simple to repair, you will have peace of mind knowing that a professional looked at it and gave you the information you needed. 

It’s also important to be aware that any significantly large cracks should not be covered or filled; you should replace them entirely if a penny can fit through the gap. So, it’s always a good idea to call a professional if the cracks are significant. 

Large cracks can be a safety hazard and can even cause a fire, and filling these cracks doesn’t always solve the issue. Once your fireplace has been repaired, you should maintain the safety by scheduling an annual inspection, recommended by the Chimney Safety Institute of America (CSIA). 

4. Fill the Mortar Joints With Mortar if They’re Cracked

If you notice cracks or gaps in the mortar joints (the part between the bricks), you should fill them with fireplace mortar. Since these cracks will be generally small and not too dangerous, you shouldn’t have any problems doing it yourself. 

Below is a guide on how to fill these gaps: 

Clean Out the Fireplace

Firstly, you’ll need to clean out your fireplace. Remove everything and sweep any dirt and dust away. You want the area to be as free from dust as possible, so make sure you get rid of as much as you can. 

Remove Loose Mortar

Chances are, there’s some loose mortar in your fireplace if you notice cracks. If that’s the case, you’ll need to chip it away using a hammer and chisel. Place the chisel between the bricks and hammer the top of it. 

The old mortar will begin to come off, making way for the new mortar. It should come out relatively easily, and you should only chisel the parts you’re going to repair. It would be best if you chiseled out enough mortar so that there’s enough space to place the new mortar (there should usually be up to an inch of space left after chiseling). 

Add the New Mortar

Once you have gotten rid of the old mortar, you can add the new one in its place. Use a cement spatula to apply the mortar in the gaps by angling the spatula. Then, you can spread the mortar by flattening the spatula and running it over the new mortar. 

If the edges are a bit rough or messy, you can use a cloth and gently wipe over the mortar you’ve just applied. 

Be sure to watch the video below if you want to see how to add mortar to a fireplace: 

Always Consult With a Professional if You’re Unsure

If you have any safety concerns or don’t feel comfortable fixing the fireplace yourself, the best thing you can do is consult with a professional. Even though most small cracks are harmless and shouldn’t be a cause for concern, it’s still good to organize an inspection every once in a while. 

When looking for a professional, you should find a certified chimney sweep; this ensures you’re getting the best-qualified chimney professional for the job. 

And don’t leave a crack untouched for too long. If you notice a large gap, get it fixed as soon as possible, particularly if you use your fireplace often. By following these steps, you should be safe from any safety hazards caused by your fireplace. 

As I mentioned earlier, it’s also vital that you organize an inspection at least once a year. Fireplaces are prone to cracks due to constant heating and cooling, so you should have a yearly inspection if you use your fireplace frequently. 


A crack in a fireplace is a common problem. Here are the most important things to remember from this article: 

  • You or a professional can cover minor damages with fire-proof cement, and you usually won’t need to consult with a professional. 
  • You should either replace the panel entirely or call a professional if you notice any large cracks in your fireplace. 
  • If there are cracks in the mortar between the bricks, fill them with new mortar. 
  • If you’re unsure how to fix a crack yourself or have any safety concerns, you should call a professional. 

Dan Westfield

Hi everyone! My name is Dan and I currently have two fireplaces, a wood-burning and a gas one. I cannot live without them and love to share my passion with you all!

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