Refractory Bricks – Advantages, Disadvantages & Uses

What Are Refractory Bricks?

Refractory bricks are unconventional types of bricks used to construct structures exposed to extremely high temperatures, such as a kiln, furnaces, and other structures. Refractory bricks are also known as fire bricks or ceramic bricks.

Fire bricks are usually manufactured in such a way that they are capable of withstanding extreme temperature changes and a high amount of heat.

Fire bricks are made up of a special type of clay, known as fire clay. The base material used for manufacturing the fire bricks is treated in such a way that it can withstand high temperatures when formed into bricks or blocks.

The refractory blocks for construction are primarily composed of two elements, silica, and alumina. Both silica and alumina are known as refractory materials.

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A refractory material or refractory is referred to as a type of material that does not decompose in conditions of high temperature. They offer excellent resistance when exposed to heat and high temperatures.

Refractory Bricks or fire bricks
Refractory Bricks

Specifications Of Fire Bricks

Let us look at some basic specifications of the refractory bricks as a masonry element.

Weight – Ideally, the weight of each ceramic block is 3-kilo grams.

Dimensions – A fire brick is manufactured in a rectangular shape. The dimensions of an ideal refractory brick vary from 9 inches x 4 inches x 1 inch to 9 inches x 4 inches x 3 inches.

Composition – The composition of refractory blocks is as follows:

Silica – Varies from 60 to 96 percent.

Alumina – Varies from 2 to 36 percent.

Other elements (Lime, Magnesium, Iron oxide, alkali) – varies from 2 to 5 percent.

Colour – The refractory blocks can be yellowish to grey to red and orangish. The grey color comes from the silica, and the yellowish shade of the fire brick is from alumina.

Temperature – The masonry fire bricks can resist the heat up to a temperature of 2100 degrees celsius (3600 degrees Fahrenheit).

Applications And Uses Of Fire Bricks

The refractory bricks or the fire bricks have several uses and applications as a masonry building material. The applications of fire bricks are further divided into two categories: –

Applications of fire bricks in high temperature, and Applications of fire bricks in low temperature.

 Let us see the applications of fire bricks below.

• The silica fire bricks are utilized for the construction of steel-making furnaces. The temperature inside the furnaces can go as high as 3000 degrees Fahrenheit.

• The refractory bricks are used as a building material to construct the inner lining of kilns, furnaces, chimneys, and similar structures that are exposed to heat and high temperatures.

• They are used to construct flame-resistant structures. The fire bricks reduce the chance of any structural defects due to high heat and temperatures.

• Fire blocks can also be used to construct the inner lining of ovens made of wood as wood is not resistant to fire.

Advantages And Disadvantages Of Refractory Bricks


The merits of using refractory blocks for the construction of structures are as given below:-

1. Relatively inexpensive – The blocks are relatively cheap as the raw materials required for manufacturing are easily available.

2. Resistant to fire – The fire bricks as building materials possess a very strong resistive property against high temperature and fire. They make the structure flame resistant and reduce the chance of structural damage due to heat.

4. The easy manufacturing process – The process of manufacturing fire blocks is more or less similar to the production process of conventional bricks used for masonry construction.

5. No requirement of skilled labours – The placement method of fire blocks is simple and similar to the traditional brick laying process. So, it does not require any special training or trained labours for laying procedures.

6. Resistant to moisture – The brick can absorb water, making it a water-resistant building material.

7. Customized sizes – though the fire blocks come in a specific size, they are also available in some customized sizes, on request to manufacturers, to suit your project’s requirements.


The demerits of using refractory blocks for the construction of structures are as given below:-

1. Heavier in weight – The refractory blocks are relatively heavier in weight, making it a bit difficult for labours to lay several blocks at a stretch. It also affects the productivity of workers.

2. Lack of soundproof property – Refractory bricks cannot absorb sound and act as a bad sound insulator.

3. Cost of bricks – The cost of refractory bricks increases with their capacity to resist heat and temperature.

Types of Fire Bricks

Refractory blocks or fire blocks are divided into three main categories:

1. Basic refractory bricks – Magnesite blocks, Dolomite blocks, Bauxite blocks.

2. Acidic refractory bricks – Ordinary fire block, Silica bauxite block, Ganister block.

3. Neutral refractory bricks – Chromium blocks, Carborundum, Chrome magnesite blocks, Spinal blocks, Forsterite blocks.


Refractory bricks or fire bricks are unconventional and new types of bricks. The uses of these bricks are limited to some extent. There are many advantages and disadvantages which we already discussed above. I hope you have now enough knowledge about it. If you have any questions let me know in the comments.

Also Read –

Fly Ash Bricks – Advantages & Disadvantages

Hollow Bricks – Advantages & Disadvantages

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