Methods of construction | Bond types in brick masonry | Brick work

 Methods of construction

Bonds in brick masonry and their formation in construction

The placing and bonding style of bricks in walls are used to classify the different types of bonds used in brick masonry wall building. The mortar filling between layers of bricks and in grooves when bricks are set near to each other and in layers in walls creates the bonding in brick masonry. Cement mortar is the most used bonding ingredient in brick masonry. Also used are lime mortar and mud mortar.

Bonds used in brick masonry wall construction include:

In brick construction, the most prevalent forms of bonding are:

1.       Header bond

2.       Stretcher bond

3.       Flemish bond

4.       English bond

Some other types of bonds are:

1. Facing bond
2. Dutch bond
3. English cross bond
4. Brick on edge bond
5. Raking bond
6. Zigzag bond
7. Garden wall bond

1.     Header bond

The shorter square face of the brick, measuring 9cm x 9cm, is the header. The term "header bond" refers to a type of bond that is also known as "heading bond." All bricks in each course are used as headers on the faces of the walls in header bonds. Stretcher bond is used to build walls with a half-brick thickness, whereas header bond is used to build walls with a full brick thickness of 18cm. In header bonds, the overlap is maintained to half the brick's width. Three quarter brick bats are used as quoins in alternating courses to achieve this.

2.     Stretcher bond

Stretcher refers to the brick's longer, narrower face, as shown in the elevation below. Stretcher bond, also known as running bond, is formed when bricks are put with only their stretchers visible, overlapping the courses of bricks below and above in the middle. The simplest repeating pattern in brick is stretcher bond. However, stretcher bond has the drawback of not being able to effectively connect adjacent bricks in full-width thick brick walls. They are only suitable for half-brick thick walls, such as those used in the building of half-brick thick partition walls. Stretcher-bonded walls are not stable enough to stand alone in cases of greater span and height. As a result, they will require supporting structures such as brick masonry columns spaced at regular intervals. Stretcher bonds are often utilised as the outer facing in steel or reinforced concrete framed structures. These can also be seen on the outside of cavity walls. Other popular uses for such walls include boundary walls, gardens, and so on.

3.     Flemish bond

Closers are put in alternating courses next to the quoin header to break vertical joints in succeeding courses. Bats are mostly employed to achieve the bond in walls with a thickness equal to an odd number of half bricks. By laying alternative headers and stretchers in a single course, Flemish bond, also known as Dutch bond, is constructed. The header of the following course of brick is placed in the centre of the stretcher in the course below, i.e. the alternating headers of each course are centred on the stretcher of the course below. Every Flemish bond alternate course begins with a header at the corner. Flemish bond has a minimum thickness of one whole brick. The disadvantage of employing Flemish bond is that it is tough to construct and requires more ability to lay properly because all vertical mortar joints must be lined vertically for optimal results. Closers are put in alternating courses next to the quoin header to break vertical joints in succeeding courses. Bats are employed to achieve the bond in walls with a thickness equal to an odd number of half bricks. For load bearing wall construction, Flemish bonds have a better appearance but are weaker than English bonds. If pointing is required for brick masonry walls, Flemish bond may be employed for a more pleasing appearance. If the walls need to be plastered, English bond is the best choice.

Flemish bond is further classified as:

1.       Single Flemish Bond

2.       Double Flemish Bond

The single Flemish bond is a hybrid of the English and Flemish bonds. In this form of construction, the exposed front side of the wall is Flemish bond, while the back surface is English bond in each course. A single Flemish bond requires a minimum thickness of one and a half bricks. The major goal of using single Flemish bond is to achieve a better aesthetic appearance on the front surface while maintaining the needed strength in the brickwork. The front and rear elevations of a Double Flemish Bond have the same appearance, with each course consisting of an alternate header and stretcher. This sort of bonding is less strong than English bonding.

4.     English bond

In brick construction, the English bond contains one stretcher course and a header course above it, i.e. two alternate courses of stretchers and headers. The stretchers in the course below are centred with headers, and each alternate row is vertically aligned. In the beginning and end of a wall following the first header, quoin closer is employed to interrupt the continuity of vertical joints. A quoin close is a brick that has been chopped in half lengthwise and used at the corners of brick walls.

Some other types of bonds as

1.     Facing bond

When the face bricks are more expensive than the other bricks, this bond is utilised to reduce the number of face bricks by utilising more stretchers. When the thickness of the face and rear bricks differs, this bond is also employed. A variety of stretcher courses are available, followed by header courses. Stretcher courses should have a thickness that is a multiple of the thickness of thinner bricks. Face bricks, for example, are 5 cm thick, while rear bricks are 3 cm thick. The height of face and back bricks will thereafter be equal after three courses of face bricks and five courses of rear bricks. Now, a header course should be provided at this height.

2.     Dutch bond

It is a variation of the English bond and consists of alternate courses of headers and stretchers, with the exception that every stretcher course begins with a three-quarter brick and every other stretcher course begins with a header.

 

3.     English cross bond

The stretcher courses break joints with each other in this variation of the English bond.

4.     Brick on edge bond

Instead of a bed, stretcher bricks are used on the margins of this form of bond. This bond has a low strength yet is cost-effective. As a result, it's commonly utilised for garden walls, compound walls, and other similar structures.

5.     Raking bond

Because headers are utilised in the interior of the wall to boost the transverse strength, walls that are more than two brick thick will become weaker in longitudinal strength. Raking bond is used to remove this flaw (rake means inclination). The bricks are put at an angle to the face of the wall in this bond.

Diagonal bond and Herring bone bond are the two types of raking bond.

·         Diagonal bond.

This bond is used in walls that are 2 to 4 inches thick. The face bricks are set first, followed by the diagonally laid bricks in this bond. The bricks' inclination should be adjusted so that they may be filled without being chopped.

·         Herring bone bond.

This bond works best on walls that are at least four bricks thick. The bricks are set at a 45° angle in both directions, starting from the centre line in this case.

When it comes to laying bricks on the floor, the raking bond design is frequently used.

6.     Zigzag bond

The zigzag bond is one in which the bricks are laid in a zigzag pattern. The Herring-bone bond is comparable to the zigzag bond. It has a pleasing aesthetic look and is hence commonly used for pavement in residential masonry projects, flooring, and pathways, among other things.

7.     Garden wall bond

Garden wall bonds are divided into two categories: English Garden Bond and Flemish Garden Bond. One course of headers is used after every three to four courses of stretchers in the English garden bond, whereas one header is used after every three or four stretchers in the Flemish garden bond.