DEFINITION OF TERMS

The definitions of some important terms used in masonry are given below.

1. Course: A course is a horizontal layer of bricks or stones.
2. Bed: This is the surface of a stone perpendicular to the line of pressure. It indicates the lower surface of bricks or stones in each course.
3. Back: The inner surface of a wall that is not exposed is called a back. The material forming the back is known as backing.
4. Face: The exterior of a wall exposed to weather is known as face. The material used in the face of a wall is known as facing.
5. Hearting: It is the interior portion of a wall between the facing and backing.
6. Stretcher: This is a brick laid with its length parallel to the face or front or direction of a wall. The course containing stretchers is known as stretcher course.
7. Header: This is a brick laid with its breadth or width parallel to the face or front or direction of a wall.
8. Arrises: The edges formed by the intersection of plane surfaces of a brick are called the arrises and they should be sharp, square and free from damage.
9. Perpends: The vertical joints separating the bricks in either length or cross direction are known as the perpends; for a good bond the perpends in alternate courses should be vertically one above the other.
10. Lap: The horizontal distance between the vertical joints in successive courses is termed as a lap; for a good bond it should be one-fourth of the length of a brick.
11. Closer: A piece of brick which is used to close up the bond at the end of brick courses is known as the closer. It helps in preventing the joint of successive courses to come in a vertical line. Generally, the closer is not specially moulded.
12. Queen closer: This is obtained by cutting the brick longitudinally in two equal parts. It can also be made from two quarter bricks, known as the quarter closers, to minimize the wastage of bricks.
13. King closer: This is obtained by cutting a triangular portion of the brick such that half a header and half a stretcher are obtained on the adjoining cut faces. A king closer is used near door and window openings to get satisfactory arrangements of the mortar joint.
14. Frog: A frog is a mark of depth about 10–20 mm, which is placed on the face of a brick to form a key for holding the mortar.
15. Bat: This is a piece of brick, usually considered in relation to the length of a brick and accordingly known as half bat or three-quarter bat.