Basics in Building Construction

Basics in Building Construction 4(2+2)

Lesson 10 : Brick Masonry

Classes Of Bricks

Quality wise, masonry bricks are classified into three classes.

1. First Class Bricks

   First class bricks are those which strictly conform to the standard size of modular bricks, i.e. 19cm x 9cmx9cm actual size, such that ten layers of bricks laid in mortar will form masonry of 1 meter height. Good bricks are manufactured from good quality plastic earth which is free from saline deposits. They are of good uniform colour. They are well burnt, hard ringing sound is emitted when two bricks are struck together. They have straight edges and even surfaces. They are free from cracks, chips, flows and nodules of lime. When immersed in water for one hour, they do not absorb water more than one-sixth of their weight, on drying, they do not show any sign of efflorescence.

2. Second Class Bricks

   Second class bricks also conform to the standard size, but they are slightly, irregular in shape and colour. They are also fully burnt, and ringing sound is emitted when two bricks are struck together. When immersed in water for one hour, they do not absorb water more than one-fourth of their weight.

3. Third Class Bricks

   These are quite irregular in their size, shape and finish. They are not burnt fully, due to which they are reddish – yellow colour. These bricks have low crushing strength. They are not used for quality brick masonry.