Brick Dimension Test and Tolerances As Per IS Code Book

Civil Engicon Team
By -
Update: May 08, 2023
In this blog post we will see the brick dimension test and tolerances as per IS Code Book along with standard procedure, apparatus required, lab test report and some important factors like brick frog size, the basic qualities of bricks and importance of brick dimension test (brick size test).

Brick Dimension Test and Tolerances As Per IS Code Book

The brick dimension test and tolerances are important factors to check the uniformity of brick size. Also, it is used to calculate (estimate) the number of bricks for masonry works. In the first part we will see types of bricks as per size and each brick dimension with tolerances.

Brick Dimension Test and Tolerances As Per IS Code Book

Types of Brick As Per Dimension (Size)

There are two types of bricks as per brick size or brick dimension:

  1. Modular brick and 
  2. Non- modular brick.

Modular Size or Standard Size of Common Building Bricks

Length (L)Width (W)Height (H)

Non-Modular Brick Size (Also May Be Used in Building Construction)

Length (L)Width (W)Height (H)

For obtaining proper bond arrangement and modular dimensions of the brick works with the non-modular sizes, the following size of the bricks may also be used:

Length (L)Width (W)Height (H)

Brick Dimension and Tolerances (Limits)

When brick dimension is tested as per IS:1077-1992, the tolerances (limits) of the brick dimensions are given flowing:

For Modular Size Bricks (Limits For 20 Bricks):

Length (L)3720 to 3880 mm[3800 ± 80 mm]
Width (W)
1760 to 1840 mm[1800 ± 40 mm]

Height (H)
1760 to 1840 mm

760 to 840 mm
[1800 ± 40 mm]
For 90 mm Height Bricks
[800 ± 40 mm]
For 40 mm Height Bricks

For Non-Modular Size Bricks (Limits For 20 Bricks):

Length (L)4520 to 4680 mm[4600 ± 80 mm]
Width (W)
2160 to 2240 mm[2200 ± 40 mm]

Height (H)
1360 to 1440 mm

560 to 640 mm
[1400 ± 40 mm]
For 90 mm Height Bricks
[600 ± 40 mm]
For 30 mm Height Bricks

Standard Test Procedure For Brick Dimension Test

The following Step-1 to Step-4 are used in the brick dimension test.

Indian Standard Used in Brick Dimension Test

  1. IS: 5454 - 1978 (Sampling Method of Brick)
  2. IS: 1077 - 1992 (Brick Test Requirements)

Apparatus Required

  1. Measuring Tape 

Brick Dimension Test Procedure

The following standard procedure is used to find the brick dimensions of bricks.

Step-1: Sampling of Bricks For Dimension Test

Twenty (or more according to the size of stack) whole bricks shall be selected at random from the sample selected as per IS: 5454 - 1978. See the table bellow for brick sampling.

Sampling Table For Brick Dimension Test - Brick Test

Step-2: Bricks Cleaning

Remove all blisters, loose particles of clay and small projections.

Step-3: Arrangement of Bricks For Dimension Test 

Then the bricks shall be arranged upon a level surface successively in contact with each other and in a straight line.

Step-4: Measurement For Brick Dimensions Test

The overall length of the assembled bricks shall be measured with a steel tape or other suitable in-extensible measure sufficiently long to measure the whole row at one stretch.

Note: Measurement by repeated application of short rule or measure shall not be permitted. If for any reason it is found impracticable to measure bricks in one row, the sample may be divided into rows of 10 bricks each which shall be measured separately to the nearest millimeter. Then all those dimensions shall be added together.

Brick Dimension Test Results 

The bricks dimensions when measured 20 bricks by arranging one beside another for length, width and height separately is the the result of bricks dimensions test.  

Brick Dimension Test Lab Report

Length of 20 bricks =
Width of 20 bricks =
Height of 20 bricks =

Brick Dimension Test Requirements

As per IS: 1077: 1992, when measured 20 bricks by arranging one beside another for length, width and height separately is the the result of bricks dimensions test. If the dimensions are under tolerance then the brick is pass otherwise fail in dimension test.

What is Brick Frog Size?

The brick frog size is given by Indian Standard as the image below. The brick frog shape and size shall conform to either one of the following shape in image. 
The primary purpose of providing a frog in a brick is to increase the surface area of mortar which is in the contact with the brick and increasing the bonding strength between the brick and the mortar. 
The frog also helps to reduce the weight of the brick and making it easier to handle during construction.

Brick Frog Size As Image 1A:

Brick frog size as 1A is given as length= 100 mm, width= 40 mm and height= 10 to 20 mm.

Brick Frog Size As Image 1B:

Brick frog size as 1B is given as length= 60 mm, width= 40 mm and height= 10 to 20 mm, corner angle of radius 20 mm.

Brick Frog Size - Brick Test
Brick Frog Size

Note: The bricks of 40 mm height as well as those made by extrusion process may not be provided with frogs.

Qualities of Good Burnt Clay Building Bricks

A good quality of burnt clay building bricks having the following qualities:

Strength: Burnt clay bricks should have sufficient strength to withstand the weight of the building and the forces that act upon it such as wind and earthquakes.

Durability: Bricks should be durable enough to withstand the effects of weathering, erosion and other environmental factors. They should also resist the effects of chemical and physical changes over time.

Uniformity: Bricks should be uniform in size, shape and color to ensure proper bonding and stability of the structure.

Porosity: Bricks should have a moderate degree of porosity to allow for adequate ventilation and moisture control within the building.

Sound Insulation: Bricks should provide sound insulation to reduce noise levels within the building.

Thermal Insulation: Bricks should provide thermal insulation to maintain comfortable indoor temperatures and reduce energy costs.

Fire Resistance: Bricks should be able to withstand high temperatures and resist the spread of fire.

Availability and Affordability: Bricks should be easily available and affordable as they are one of the most common building materials used in construction.


Why Dimension Tests on Bricks are Important?

Dimension test of bricks are important because the brick dimensions play a crucial role in construction. Understanding the importance of dimension test is essential for builders, engineers and architects alike. The size and shape of bricks impact the overall design, strength and durability of a structure. 

The size of bricks can vary depending on the type of construction and region. So that is essential to maintain uniformity in the dimensions to ensure structural integrity. Inconsistent brick dimensions can lead to weak points in the structure which can cause the building to collapse over time.

The dimensions of bricks affect the strength and durability of a structure. A thicker brick will generally be stronger and more durable than a thinner brick. Similarly, the size of the brick determines the size of the mortar joint which is crucial for maintaining the stability of the structure.

Why Standard Brick Size?

The reason behind standard brick size is to maintain the uniformity of brick's shape-size, strength and masonry structures. By using standard size of brick dimensions, we can also estimate the number of bricks required in project.

What is Brick Dimension Test IS Code?

Brick Dimension Test IS Code is IS:1077-1992 (Brick Test Requirements). This code book deals with the dimension test of bricks for both modular or standard bricks and non-modular bricks.

What is the Dimension Test For Brick?

Dimension test for brick is the measurement of length, width and height of the 20 bricks. Each measurements should be under the specified limits.

A Tolerance (+/-) in Length, Width and Height Respectively For Brick Dimension Test?

When brick test is conducted, 20 bricks are taken to measure the dimension test of bricks. The tolerance (+/-) in length, width and height is 4600 ± 80 mm, 2200 ± 40 mm and 1400 ± 40 mm respectively.

What are Brick Test IS Code?

Brick test IS Code books are all parts of IS:3495 and IS:1077.


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