Brick Masonry

Various Types of Brick Masonry

• Stretcher: A stretcher is the longer face of the brick (i.e. 19 cm × 9 cm) as seen in the elevation of the wall. A course of bricks in which all the bricks are laid as stretchers on facing is known as a stretcher course or stretching course.
• Header: A header is the shorter face of the brick (i.e. 9 cm × 9 cm) as seen in the elevation of the wall. A course of bricks in which all the bricks are laid as headers on the facing is known as header course or heading course.
• Lap: Lap is the horizontal distance between the vertical joints of successive brick courses.
• Perpend: A perpend is an imaginary vertical line which includes the vertical joint separating two adjoining bricks.
• Bed: Bed is the lower surface (19 cm × 9 cm) of the brick when laid flat.
• Closer: It is a portion of a brick with the cut made longitudinally, and it used to close up bond at the end of the course. A closer help in preventing the joints of successive courses (higher or lower) to come in a vertical line. Closers may be of various types as defined below.

• Queen-closer: It is a portion of a brick obtained by cutting a brick lengthwise into two portions. Thus, a queen-closer is a brick which is half as wide as the full brick. This is also known as queen-closer-half.
  When a queen-closer is broken into two pieces, it is known as queen-closer-quarter. Such a closer is thus a brick piece which is one-quarter of the brick size.
• King closer: It is the portion of a brick which is so cut that the width of one of its end is half that of a full brick, while the width at the other end is equal to the full width. It is thus obtained by cutting the triangular piece between the centre of one end and the centre of the other (adjacent) side. It has half-header and half-stretcher face.
• Beveled closer: It is a special form of a king closer in which the whole length of the brick (i.e. stretcher face) is beveled in such a way that half width is maintained at one end and full width is maintained at the other end.
• Mitred closer: It is a portion of a brick whose one end is cut splayed or mitred for full width. The angle of splay may vary from 45° to 60°. Thus, one longer face of the mitred closer is of full length of the brick while the other longer face is smaller in length.
• Bat: It is the portion of the brick cut across the width. Thus, a bat is smaller in length than the full brick. If the length of the bat is equal to half the length of the original brick, it is known as half bat. A three-quarter-bat is the one having its length equal to three-quarters of the length of a full brick. If a bat has its width beveled, it is known is beveled bat.
• Arris: It is the edge of a brick.
• Splays: These are special moulded bricks which are often used to form plinth.
• Dogleg or angle: It is also a special form of moulded bricks which are used to ensure satisfactory bond at quoins which are at an angle other than right angle. The angle and lengths of the faces forming the dogleg vary according to requirements. These are preferred to mitred closer.
• Quoin: It is a corner or the external angle on the face side of a wall. Generally, quoins are at right angles. But in some cases, they may be at angles greater than 90° also.
• Frog or kick: A frog is an indentation in the face of a brick to form a key for holding the mortar. When frog is only on one face, that brick is laid with that face on the top. Sometimes, frogs are provided on both the faces. However, no frogs are provided in wire-cut bricks. A pressed bricks has two frogs (as a rule) and a hand-made brick has only one frog.
• Racking back: It is the termination of a wall in a stepped fashion.
• Toothing: It is the termination of the wall in such a fashion that each alternate course at the end projects, in order to provide adequate bond if the wall is continued horizontally at a later stage.

Exogenous Trees

• These trees increase in bulk by growing outwards and distinct consecutive rings are formed in the horizontal section of such a tree.
• These rings are known as the annual rings because one such ring is added every year and these rings are useful in predicting the age of tree.
• The timber which is mostly used for engineering purposes belong to this category.
• Exogenous trees are further subdivided into two groups.
  (i) Conifers: They show distinct annual rings. Example: pine, spruce, deodar.
  (ii) Deciduous: They do not show distinct annual rings. Example: Teak, sal, oak, babul.
• Conifers are also known as evergreen trees and leaves of these trees do not fall till new ones are grown. As these trees bear cone-shaped fruits, they are given the name conifers. These trees yield soft woods.
• Deciduous trees are also known as broadleaf trees and leaves of these trees fall in autumn season and new ones appear in spring season. Timber for engineering purposes is mostly derived from deciduous trees. These trees yield hard woods.

Table. Comparison of Soft Wood and Hard Wood