Last updated: August 8, 2021

Welcome to our big fire brick test 2021. Here we present all the fire bricks that we have tested in detail. We have compiled detailed background information and added a summary of customer reviews on the web.

In this way, we would like to make your purchase decision easier and help you find the best fire bricks for you.

You will also find answers to frequently asked questions in our guide. If available, we also offer interesting test videos. Furthermore, you will also find some important information on this page that you should definitely pay attention to if you want to buy fireclay bricks.




Summary

  • Fire bricks are industrially produced, refractory bricks that can withstand temperatures of up to 1,500°C.
  • The higher the aluminium oxide content of the firebricks, the more heat-resistant and fire-resistant they are.
  • Fire bricks are an inexpensive way to fireproof your stove.

The Best Fire Bricks: Our Choices

Guide: Questions you should ask yourself before buying fire bricks

What are fire bricks?

Fire bricks are bricks that are used for lining stoves, fireplaces or chimneys because of their refractory material.

Fire bricks are a mix of raw clay and 10 to 45% aluminium oxide. Fireclay bricks are very heat-resistant and can store heat well, making them particularly suitable for stoves.

In the production process, the raw clay is first pre-fired. Then the aluminium oxide is added and the resulting "fire grain" is further fired at high temperatures. This mass is then shaped by casting or pressing and the result is finished fire bricks. Fire bricks can also be processed afterwards.

Fireclay bricks are particularly heat-resistant and are therefore well suited for a fireplace. (Image source: unsplash.com / Hayden Scott)

What are fire bricks used for?

Because fire bricks are very heat-resistant and can store heat well, they are mostly used to line stoves.

In fireplaces, for example, the advantage is that the fire bricks release the heat of the wood fire only slowly, which increases the efficiency of the fireplace. The situation is similar with a garden fireplace that is lined with fire bricks. You can then use the fireplace optimally as a heat source for garden parties.

You will also often find fire bricks in chimneys, where their refractory properties are used. You will also often find fire bricks in pizza ovens, as they offer the best conditions for baking a classic stone oven pizza with a crispy base.

How can I work with fire bricks?

Even though fire bricks are shaped during production, you can of course work on them afterwards. However, there are a few things you should bear in mind, because fire bricks are very sensitive.

Fire bricks are very brittle, which is why you should refrain from applying a lot of pressure or vibrations if you want to drill a hole in the bricks, for example. This means that you should not use a percussion drill, but rather the normal drilling function with a high speed and as little pressure as possible.

When cutting, it is best to use an angle grinder or a Flex with a diamond cutting blade. As with drilling, you should apply as little pressure as possible, as the fire bricks rarely withstand vibrations.

When working on fire bricks, you should also make sure to wear a mouth guard and protective goggles. The processing of fire bricks generates a lot of dust.

How much do fire bricks cost?

Fire bricks are considered a fairly inexpensive alternative to other refractory materials. However, how expensive they really are in the end depends on the quality and thickness of the bricks you end up choosing.

As a general rule, the higher the proportion of aluminium oxide, the higher the heat storage capacity of the stone and thus also the price. It is most effective if you choose an aluminium oxide content between 30 and 45%.

type price
acid fire (10 to 30% aluminium oxide content) from a few euros
normal fire (30 to 45% aluminium oxide content) from 10 to 15 €

What alternatives are there to fire bricks?

The best-known alternatives to fire bricks are natural stone, ceramic and vermiculite.

Both natural stone and ceramic are visually much more appealing than firebricks. Ceramic is probably the best-known form of heat accumulator, but natural stone is also in no way inferior to ceramic in this respect. However, you must bear in mind that neither natural stone nor ceramic is suitable for replacing a combustion chamber lining.

Vermiculite is also known as mica slate. This is mineral granulate that is pressed into slabs under air pressure. Just like ceramic or natural stone, you can use it to line combustion chambers. The difference, however, is that vermiculite is not suitable for heat storage.

There are different fireplace linings. Each fireplace lining has its advantages and disadvantages. (Image source: pixabay.com / rawpixel)

However, this also has an advantage. Due to the low thermal conductivity, the temperatures in the combustion chamber can be increased significantly. This increases the performance of the stove, but at the same time reduces emissions. The reason for this is that the number of emitted particles decreases as the temperature rises.

Furthermore, vermiculite is also lighter than fire brick, but just as prone to breakage. As a rule, vermiculite must be replaced after three years at the latest.

Type Description
Fire Material: Mix of clay and aluminium oxide, heat and fire resistant, good heat storage
Ceramic Material: Clay, good heat storage, not suitable for the combustion chamber
Natural stone Material: Stone, good heat storage, like natural stone not suitable for lining the combustion chamber
Vermiculite Material: Mineral granulate, suitable as a combustion chamber lining, no heat storage due to low thermal conductivity

Buying criteria: You can use these factors to compare and evaluate fire bricks

Below you can find a list of aspects that you can use to distinguish between fire bricks. The criteria that you can use to compare fire bricks with each other include:

  • Strength/Porosity
  • Age/duration of use
  • Heat resistance/fire resistance
  • Thermal conductivity

In the following paragraphs, we will explain what is important in each criterion.

Strength/Porosity

Although fire is very good at storing heat and is also very heat-resistant, the artificial stone becomes porous with increasing age.

This means that you should make sure that the fire brick is brittle, but if it is already cracked or starting to crumble, these signs either indicate that the brick is of poor quality or has already been in use for too long.

For this reason, it is not advisable to buy used fire bricks online, as you will not be able to enjoy them for long. It is better to go to a specialist shop for detailed advice so that you don't have to replace your firebricks after just a few months.

Age/duration of use

As already mentioned, fire bricks are brittle, but if they are already porous or cracked, this indicates that the bricks are very old or have been in use for a long time.

How often fire bricks need to be replaced depends on the intensity of use. The more often and intensively you use your firebricks, the faster they will age and the faster they will need to be replaced. It is difficult to determine an average half-life, but you can assume that a higher aluminium oxide content is beneficial for the service life.

Heat resistance/fire resistance

After firing, firebrick is extremely heat-resistant and can withstand temperatures of up to 1,500 °C. The higher the proportion of firebrick, the greater the heat resistance. The following applies: the higher the proportion of aluminium oxide contained, the higher the heat resistance.

You can distinguish between so-called acid fire and normal fire. Acid fire has an aluminium oxide content of between 10 and 30 % and is therefore cheaper than normal fireclay, although the heat resistance is also limited in comparison. Normal fire has an aluminium oxide content of between 30 and 45%, which increases the heat resistance, but also the price.

Thermal conductivity

Similar to the heat resistance, the thermal conductivity also increases with increasing aluminium oxide content. In principle, fire already has a high thermal conductivity. However, if you want to use this even more, for example in the form of a garden stove, then it is advisable to place value on a higher aluminium oxide content.

A distinction is made between acidic fire and normal fire in terms of thermal conductivity and heat resistance.

Facts worth knowing about fire bricks

Why do my fire bricks crack or crumble?

Although fire bricks are very heat-resistant and can conduct heat well, they become porous with increasing operating time. For this reason, fire cladding must be replaced at regular intervals. How often this is the case depends on the intensity of use.

In addition, fire bricks are very sensitive to impacts. This means that your fire bricks can also be cracked because, for example, you hit the fire bricks too hard with the piece of wood when adding firewood and damaged them.

For this reason, care and caution are necessary with fire bricks, not only when working on them, but also when using them.

How do I repair fire bricks?

If your fire bricks are basically still OK and are only cracked in one place, the best way to patch them is with fire mortar. This is also used to join two fire bricks together.

However, if your fire bricks are already starting to crumble, it is a sign that your bricks are too old. Minor faults can still be repaired, but if they are already crumbling away over a large area, then it is high time to replace your bricks.

How do I clean and care for fire bricks?

In most cases, fire bricks become sooty during use. The reason for heavy sooting is that damp wood is usually used. To take care of your bricks in this respect, you should make sure that you only use dry wood.

Soot deposits on the stones can be scraped off with a spatula, for example. For cleaning, you can also use water and a special sponge with a scraper side.

It is important that the stones are completely dry before you use the stove again. In addition, you should regularly remove the ash that has formed in order to avoid larger amounts of dirt.

How do I install or replace fire bricks correctly?

Theoretically, you can replace fire bricks yourself. The advantage is that most bricks for a stove are already offered by the manufacturer to fit the corresponding model, so that you do not have to cut and adjust them at home, but only insert them.

However, if you don't have any suitable stones, you can also adapt your new stones yourself using a flex with a diamond cutting blade. To get the right shape, you can use the old stones as a template.

Then all you have to do is put the stones in the kiln.

If you are building an individual stove yourself and need to join the bricks together, fire mortar is recommended.

To give you an idea of how to change the interior of your fireplace, we have selected a video for you.

Where can I dispose of fire bricks properly?

Fireclay bricks do not count as construction waste and must therefore be taken to a waste transfer station as construction site residual waste. However, you can dispose of small quantities of fire bricks, for example individual fragments, in the residual waste bin.

However, if you have fire bricks from ovens that were manufactured before 1980, they must be packed dust-tight. The reason for this is the danger of possible asbestos contamination of the bricks.

Photo source: 123rf.com / dolgachov

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