What Is Refractory Brick?

Mary McMahon
Mary McMahon

Refractory brick, also known as fire brick, is a type of specialized brick which is designed for use in high heat environments such as kilns and furnaces. Numerous companies manufacture refractory brick in a range of shapes, sizes, and styles, and it can be ordered directly through manufacturers or through companies which supply materials to people who work with high heat processing of materials. High quality fire brick has a number of traits which make it distinct from other types of brick.

Refractory brick is sometimes used to make fireplaces.
Refractory brick is sometimes used to make fireplaces.

The primarily important property of fire brick is that it can withstand very high temperatures without failing. It also tends to have low thermal conductivity, which is designed to make operating environments safer and more efficient. Furthermore, refractory brick can withstand impact from objects inside a high heat environment, and it can contain minor explosions which may occur during the heating process. It may be dense or porous, depending on the design and the intended utility.

This brick product is made with specialty clays which can be blended with materials such as magnesia, silicon carbide, alumina, silica, and chromium oxide. The exact composition of refractory brick varies, depending on the applications it is designed for, with manufacturers disclosing the concentrations of ingredients and recommended applications in their catalogs. Using fire brick which is not designed for the application can be dangerous, as the bricks may fail, cracking, exploding, or developing other problems during use which could pose a threat to safety in addition to fouling a project.

Even though it is specifically designed for high heat environments, refractory brick will eventually start to fail. It can crack, flake, or break down over time, necessitating regular inspection of environments where this product is used. If damaged bricks are identified, they need to be removed and replaced with new bricks to ensure that the device operates as intended, and to reduce the risk of injuries, equipment failure, and other problems. The bricks can also accumulate soot and other materials through routine use, and they may need to be scrubbed down periodically.

Some places where fire brick can appear include: fireplaces, wood stoves, cremation furnaces, ceramic kilns, furnaces, forges, and some types of ovens. The earliest refractory bricks were developed around the 1800s, with several inventors contributing radical reworkings to make such products safer and more reliable. Companies continue to experiment with recipes and manufacturing process to develop even better products which will increase efficiency and safety while cutting down on maintenance costs.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


We want to use refractory bricks in a vertical furnace where we are using pet coke as fuel. Kindly tell us which type of brick is more suitable.


How much heat can a clay brick withstand?


My uncle is all fired up (pun intended) about using his ceramic grill. He has gotten pretty creative with the meals he creates. He actually uses refractory brick in his cooker to set his pizza stone on so he can cook pizza in his ceramic grill. I have to admit that it is quite delicious. He was able to order the bricks off of the Internet.


My aunt loves creating ceramic decorative pieces. She has a Paragon kiln for firing her pieces. It is lined with firebrick (refractory brick). One of the great things about this is that when the bricks do break down they can be replaced. I helped her just last week replace one of the firebricks in her kiln.

Post your comments
Forgot password?