Repairing Fireplaces with Fire Cement: Step-by-Step Instructions


Oven time, some cracks may appear on your fireplace, even if you take proper care of it. You may also experience creosote build-up, low-heat output, and some other problems (like problems with a chimney). Regardless of the type of the fireplace, you should always fix what is damaged as soon as possible. Cracks are rather small at first, and it’s possible to repair everything just by using fire cement. It gets harder and harder later, so it is not worth delaying. Quick repair will not only fix the cracks which pose a fire hazard, but also will prevent any further deterioration. How to repair a fireplace with fire cement properly? Read on to find out more about repairing fireplaces with fire cement, step by step!

Why use fire cement to repair fireplaces?

Fire cement is nothing but a ready and mixed combination of inorganic fillers and thermosetting resins, which is resistant up to 1250ºC. This is something different from regular cement, and the main difference is the ability to withhold high temperatures. No other product can withhold such high temperatures equally well. Fire cement offers high adhesion, excellent heat resistance, and resistance to thermal shock.

What’s more, this mortar has air setting properties, it’s durable, reliable, and asbestos-free. You can actually use it on flue bricks, fire bricks, fire grates, solid fuel stoves, boilers and so on – fire cement is suitable for many applications. For example, it is recommended to repair a fire brick to the rear of open fires. Fire cement may also prove useful in the case of gas fireplace repairs.

How to repair fireplaces with fire cement?

The process of repairing a fireplace consists of a few steps. Remember that you can, of course, use one of the fireplace repair services. However, we believe that our guide clearly explains all the steps you need to take to fix your fireplace with fire cement.

Start off by getting all the required materials

The first step is buying the most important product, which is fire cement, and then equipping yourself with gloves, safety glasses, clean cloth or sponge, and brush, needed to spread the cement. Know where exactly you have to apply fire cement. Repairing is required in areas with gasps, cracks, damaged joints etc.

Clean the surface that needs fixing

The next step is all about cleaning the surface that needs fixing. Vacuum, clean, wipe it up. Do whatever it takes to make the area as clean as possible. The previously mentioned clean cloth and sponge may come in handy. There is no place for debris, soot, ash, dust, or contaminants – get rid of them.

Mix fire cement (optional)

Follow the manufacturer’s instructions, keeping in mind that different products may have different application guidelines. If you have fire cement requiring mixing with water, this is a good time for it. If you bought fire cement in a ready-to-use pre-mixed form, you can skip this step.

Apply fire cement where needed

Take your mortar and spread it into the hole in your fireplace. Remember that when you make this kind of repair, the best option is to go in one direction – it looks the best then. Use as much fire cement as needed, just make sure that everything cracked or damaged is covered. If it is – let everything dry. And that’s it!

When you first use your fireplace, fire it up gradually

The very last step is to fire the fireplace up gradually. To be more precise, when you first use your fireplace after a repair, start with a small fire and increase the heat gradually. Thanks to this strategy, fire cement can cure properly. It also prevents thermal shock.


The process of repairing is a five-step process if we take into account the things we mentioned above. You need to equip yourself with the required materials, clean the area that needs fixing, mix fire cement (however, this step is optional), apply fire cement and heat the fireplace up gradually at the very end. You can contact a company which provides the fireplace repair service for further information if you don’t feel able to repair your fireplace on your own. However, we strongly recommend at least attempting to repair it (unless the damage is severe, then it may take more extensive repair work). Furthermore, you should also remember about regular servicing, which will help you keep the fireplace in a good condition.